The biological method is the technique in which there is the use of living microorganisms or its product for the control of pests. This method uses the microbes which act as predators or enemies of the target pest species. The biological control method is often relatively inexpensive because the method uses the microorganisms which can be easily cultured. These are beneficial microorganisms which are used, so they do not contribute the pollution. If biocontrol agents are introduced in any area, survive for multiple years and become self-perpetuating. They will spread over a large area over time and continue to exist for a very longer period. 

Integrated pest management (IPM) is the programme which particularly focuses on agricultural crop diseases and its management. According to It, the use of biological control agent or other living organisms can control the plant diseases. Biological control is environment-friendly and effective against a broad range of insect pests and relatively easy to adopt.

Bioconcentration is the process of ingestion and retention of the chemical substance in an organism. It mainly occurs in the aquatic organism by the exposure of waterborne chemicals.  

Biological control is a component of an integrated pest management strategy. Biological control is keeping the population of an organism or harmful pests and weeds under check by means of natural predators, parasites and amensals. 

Trichoderma fungus is a common biological control for a range of plant pathogens.

Thurioside is obtained from bacteria Bacillus thuringiensis, used as a bioinsecticide.

Bacillus thuringienesis  is a potent agent that can function as a biopesticide.

Xanthomonas campesteris is bacterial species that causes a variety of plant diseases,whereas the rest can be used as biopesticide.

Viruses of genus Nucleopolyhedrovirus , Baculoviruses are species-specific narrow spectrum biocontrol agents for plant pathogens.

Bacillus thuringiensis are regarded as excellent biocontrol agents for butterfly caterpillars, and hence used as bioinsecticide.

• 2,4-Dichlorophenoxyacetic acid (2,4-D) is the third most commonly used herbicide all over the world.  The health hazards of 2,4-D to humans include that it may induce cytogenetic damage in human lymphocytes, irreversible eye damage, hepatotoxicity and nephrotoxicity. Many methods are proposed for treatment of chemical pollution, however, the safest and the cheapest one is the use of microorganisms for biodegradation of these pollutants. the most biologically active strains against 2,4-D proved to belong to the genera Pseudomonas, Achromobacter, Flavobacterium, Nocardia, Streptomyces and Aspergillus.
• 1,1,1 -trichloro-2,2-bis (p-chlorophenyl)ethane (DDT) is one of the best synthetic pesticides. It was used to control mosquitoes spreading malaria, typhus and other insect-borne diseases among both military and civilian populations. After the war, DDT was made available for use as an agricultural insecticide. It was used extensively for the control of grass grub {Costelytra zealandica White). It was necessary to introduce microbes to degrade or control DDT in soil. It was done so by using DDT-degrading strain of E. aerogenes.
• So all the above options are correct.

Rotenone is a crystalline isoflavone used as an insecticide. It occurs naturally in several plants. example jicama vine plant, and the roots of Fabaceae.

Pyrethrum is a genus of plants which are cultivated as ornamentals. It is a natural insecticide made from the dried flower heads of Chrysanthemum cinerariifolium. Pyrethroids are synthetic insecticides derived from natural Pyrethrum (pyrethrins). The compound enhances the effect of toxicity to insects. These compounds target the nervous system of the insects. They are commonly used as insect repellants. 

Biopesticides are those biological agents that are used for the control of weeds, insects and pathogens. examples of biopesticide are as follows-
a) Nicotine- tobacco
b) Azadirachtin- neem

Integrated pests management is a method which uses the natural agents like the microbes and insects to control the population of other harmful pests and insects. Thus, it is an integrated method for the control of the pests, insects, harmful disease causing agents, etc. The different methods to control pests are physical, biological, chemical, mechanical and cultural. 

Integrated pests management is a method which uses the natural agents like the microbes and insects to control the population of other harmful pests and insects. The different methods to control pests are physical, biological, chemical, mechanical and cultural. The physical method involves controlling physical parameters like cold, high temperature, humidity, light, etc. Manipulation of these parameters help in controlling pests.

Integrated pests management is a method which uses the natural agents like the microbes and insects to control the population of other harmful pests and insects. Mechanical control is applied when the pests reach an unacceptable level. This method includes techniques like bagging fruit, sieves, hand-picking, barriers, traps, vacuuming and tillage to disrupt breeding. 

Eight basic principles are included in integrated pest management.

Integrated pests management is a method which uses the natural agents like the microbes and insects to control the population of other harmful pests and insects. Different methods are used for the control of the pests. When the plant and the animals are affected by the pests or disease, they are shifted to a place and quarantined to prevent the other plants and animals from getting affected. These are considered under the regulatory methods. 

Integrated pests management is a method which uses the natural agents like the microbes and insects to control the population of other harmful pests and insects. Mechanical control is applied when the pests reach an unacceptable level. This method includes techniques like screens, beating with stick, bagging fruit, sieves, hand-picking, barriers, traps, vacuuming and tillage to disrupt breeding. 

Biological control is a method to control pest by using living microorganisms or its product. It is used as natural enemies like the predators, parasites, pathogens, and competitors to suppress and maintain populations of a target pest species (insects, mites, weeds, plant pathogens, and other pest organisms). This is the most widely used method in today's world for the control of pests. 

Bacillus thuringiensis are bacteria that act as biological insecticide.

Bacillus thuringiensis have Bt toxin encoded by cry genes forming cry proteins.

The egg pathogenic fungus Paecilomyces lilacinus is a biocontrol fungus for check from nematodal pathogens of plants.

The fungus Trichoderma species are free-living fungi that are very common in root ecosystems and are effective biocontrol agents of several plant pathogens.

Answer is option C i.e. "Marigold"
Biodegradable insecticides are types of insecticides derived from natural materials as plants, bacteria, etc. Bioinsecticide from marigold flowers contains chemicals called thiophenes which are toxic to the larvae of mosquitoes that carry malaria and yellow fever. Bioinsecticide made from marigold also contains repellent against major tomato pests: whiteflies, thrips, and spider mites.

Baculoviruses are used as biological control agents and in intrinsic farming because of all these above characteristics.

Trichoderma,Nucleopolyhedro virus,Bacillus thuringiensis,Lady Bird beetle are all used as biopesticides.

Soil bacterium Bacillus thruingiensis (Bt) produces proteins that kill certain insects like lepidopterans (tobacco dudworm, armyworm), coleopterans (beetals) and dipterans (files, mosquitoes).Bacillus thuringinesis forms some intracellular protein crystals. These crystals contain a toxic insecticidal protein. The Bt toxin protein exists as inactive toxin and is coverted into an active form due to the alkaline pH of the alimentary canal that solubilities the crystals. The activated toxin binds to the surface of midgut epithelial cells and create pores which cause cell swelling and lysis and finally cause death of the insect.

Soil bacterium Bacillus thruingiensis (Bt) produces proteins that kill certain insects like lepidopterans (tobacco budworm, armyworm), coleopterans (beetles) and dipterans (flies, mosquitoes). Bacillus thuringinesis forms some intracellular protein crystals. These crystals contain a toxic insecticidal protein. The Bt toxin protein exists as an inactive toxin and is converted into an active form due to the alkaline pH of the alimentary canal that solubilities the crystals. The activated toxin binds to the surface of midgut epithelial cells and creates pores which cause cell swelling and lysis and finally cause the death of the insect.

Soil bacterium Bacillus thruingiensis (Bt) produces proteins that kill certain insects like lepidopterans (tobacco dudworm, armyworm), coleopterans (beetles) and dipterans (flies, mosquitoes). Bacillus thuringinesis forms some intracellular protein crystals. These crystals contain a toxic insecticidal protein. The Bt toxin protein exists as an inactive toxin and is converted into an active form due to the alkaline pH of the alimentary canal that solubilities the crystals. The activated toxin binds to the surface of midgut epithelial cells and creates pores which cause cell swelling and lysis and finally cause the death of the insect.

Soil bacterium Bacillus thruingiensis (Bt) produces proteins that kill certain insects like lepidopterans (tobacco budworm, armyworm), coleopterans (beetles) and dipterans (flies, mosquitoes).Bacillus thuringinesis forms some intracellular protein crystals. These crystals contain a toxic insecticidal protein. The Bt toxin protein exists as an inactive toxin and is converted into an active form due to the alkaline pH of the alimentary canal that solubilities the crystals. The activated toxin binds to the surface of midgut epithelial cells and creates pores which cause cell swelling and lysis and finally cause the death of the insect.

Trichoderma species are free living fungi that are very common in the root ecosystems. They are effective biocontrol agents of several plant pathogens like Fusarium, Phytopthora etc and used in the treatment of plant diseases.

Soil bacterium Bacillus thruingiensis (Bt) produces proteins that kill certain insects like lepidopterans (tobacco budworm, armyworm), coleopterans (beetles) and dipterans (flies, mosquitoes).Bacillus thuringinesis forms some intracellular protein crystals. These crystals contain a toxic insecticidal protein. The Bt toxin protein exists as an inactive toxin and is coverted into an active form due to the alkaline pH of the alimentary canal that solubilities the crystals. The activated toxin binds to the surface of midgut epithelial cells and creates pores which cause cell swelling and lysis and finally cause death of the insect.

Xanthomonas campestris is not used as a biopesticide. Bacillus thuringiensis is used as a microbial biocontrol agent. Trichoderma harzianum is a free-living fungi, common in soil and root ecosystems. It is an effective biocontrol agent of several plant pathogens. Viruses of the family Baculoviruses are pathogens that attack insects and other arthropods. The majority of baculoviruses used as biological control agents belong to genus Nucleopolyhedrovirus. So, the correct answer is 'Xanthomonas campestris'.

Biopesticides are those biological agents or their products that are used for the control of weeds and insects (pathogens). A most important example is the soil bacterium, Bacillus thuringiensis.

So, the correct answer is ' 3'.

Trichoderma are fungi and present in the soil as avirulent symbionts.

Xanthomonas campestris is an aerobic, gram-negative rod known to cause the black in crucifers by darkening the vascular tissues. Host-associated, over 20 different pathovars of V.Campestris have been identified by their distinctive pathogenicity on a wide range of plants including crops and wild plants.

Fabrics fibers K and N are usually laminated to or coated with a waterproofing material such as rubber, polyvinyl chloride (PVC), polyurethane (PU), silicone elastomer, fluoropolymers, and wax

The third generation pesticides are basically the modified forms of the insect hormones that show a great specificity to the pest or insect targetted. The juvenile hormone analogues such as methoprene, hydroprene and fenoxycarb do not kill the insect directly but prevent the development of their larvae. Gradually, they decrease the population of the insect as the adult insects will never be formed.

Baculoviruses are pathogens that attack insects and other arthropods. The majority of them used as a biological control agents are in the genus Nucleopolyhedrovirus.These viruses are excellent candidates for species-specific, narrow spectrum insecticidal applications. Infection with baculoviruses occurs when susceptible hosts eat virus particle present on foliage and dies. These are important in organic farming because of their specific action on harmful insects without causing any damage to beneficial insects as well as to the environment.