Hydra vulgaris - is freshwater hydra, Hydra gangetic - Fresh water hydra, Obeila - sea water, Physalia - sea water. 

Common commercial hides include leather from cattle and other livestock animals, alligator skin and snake skin. All are used for shoes, clothes and other fashion accessories. Animal hides are stretched, dried, and tanned. Most hides are processed from domesticated animals. India is the largest exporter of hides and skin to the world.

Murrah has a high milk yield of milk and gives about 1900 to 2200 liters of milk during its lactation period.

Explanation: Foot and mouth disease (FMD) is a highly contagious disease of cloven footed animalsincluding cattle, sheep, goat and pigs. This disease is endemic in India and producing serious economic losses to the country due to the ban on export of livestock products to other countries and reduced productivity of diseased animals. Anthrax -Synonyms: Splenic fever, fanshi, kalpuli Ban. It is an acute widespread infectious disease of all warm blooded animals specially cattle, buffalo, sheep, goat. It is communicable to man i.e. Zoonotic disease. It is soil-borne infection. It usually occurs after major climatic change. The disease is enzootic in India. Etiology: This disease is caused by bacteria called Bacillus authracis. Mastitis-denotes an inflanation of the udder, this disease is responsible for heavy financial losses to dairyman due to discarding of abnormal milk, reduced milk production and butter fat, decreased market value of cow and cost of drugs and veterinary services. In addition to this, the mastitic milk causes dreadly diseases like tuberculosis, brucellosis, sore throat, food poisoning etc. in human beings.

Indian buffaloes are important source of milk supply today and yield nearly three times as much milk as cows. The average annual milk yield of a buffalo is 491 liters as against 173 liters of a cow in India. 

Cattle are domesticated animals from several thousands of years by humans. They do help us in several different ways. They are widely used for dairy production, that is for the production of milk. They provide us good manure, which can flourish the crops raised by humans. Cattle dungs were used as a fuel in ancient times. People used to travel on back of cattles even for a long distance and thus, helps in transport too.

Petrolatum is soft paraffin wax. Waxes are esters of fatty acids with alcohol of high molecular weight instead of glycerol. They form water-insoluble coatings on hair and skin in animals and stems, leaves and fruits of plants.

The rearing of silkworm for silk is known as Sericulture.  In sericulture the silkworm are reared at appropriate temperature and humidity to get silk thread from cocoons.
Hence correct option is A ( Sericluture).

India has the largest number of cattle in the world.

Buffalo is useful in producing milk, butter and leather.

Apis cerana are small honey bees. There are eight subspecies of A. cerana out of which two subspecies are predominant and used for apiculture in India. They have black stripes on their abdomen and they live close to hilly areas and are sometime seen in plain regions as well.