The process that is used to separate grain from stalks etc. is threshing. In this process, the stalks are beaten to free the grain seeds.

A farmer with less water resources should grow selected short term crops(e.g, paddy, green leafy vegetables) which have a life span of one or less than one year as this process provides cash flow and takes care of day to day operations cost of the farm. Another effective method called drip irrigation is also helps to save water and nutrients as the water drips slowly and directly to the roots of the plant and the evaporation is minimized. So, the correct option is "(i),(iii)".

The primary cause of heat buildup in cities is insolation i.e. absorption of solar radiation by roads and buildings. Storage of this heat by building material results in subsequent re-radiation. Due to transpiration of plant surface, its temperature does not rise 4-5 degree above the ambient and sometimes is cooler. This then translates into the cooling of the environment. Hence rooftop gardening reduces the overall heat absorption of the building which then reduces energy consumption. Thus the correct answer is option A.

Precision farming is a concept of crop management based on observing, testing, measuring and responding to field variability in crops. In this farming, they use research in weathers, test the soil temperature, humidity, growth and moisture.

A polyhouse also called polytunnel is a tunnel made of polyethelene semi-circular, square or elongated in shape. Solar radiations are used to heat up the interior. This warms the plants, soil, and other things inside the building faster than heat can escape the structure. This warmed air in interior surfaces is retained in the building by the roof and wall.Temperature, humidity and ventilation is controlled by equipment fixed in the polytunnel or by manual opening and closing of flaps. Thus plants grow under the complete controlled condition in polyhouse farming. 

Drip irrigation is the best for watering plants in a polyhouse. In drip irrigation system, water under high pressure is forced through nozzles arranged on a supporting stand at about 1 feet height. This enables watering at the base level of the plants.This watering system ensures that water does not fall on the leaves or flowers as it leads to disease and scorching problems.

Precision farming is a farming system in which inter and intra-field variability in crops are observed and responded to. The goal of precision farming is using information technology in decision making for optimizing returns on inputs and at the same time preserving resources. Polythene sheets prevent weed and soil pathogens growth. They accelerate the uptake of micronutrients from the soil. They reduce the irrigation water requirement of the crop and thus conserve soil moisture. Thus polythene sheets are used in precision farming.

Roof gardening is a type of garden which is started on the roof of the building. It is an ideal way of urban gardening.  The advantage of this gardening is it helps in runoff stormwater, these are energy efficient, improves air quality, etc.

Drip irrigation also called micro irrigation system is the best for watering plants in a polyhouse. In drip irrigation system, water under high pressure is forced through nozzles arranged on a supporting stand at about 1 feet height. This enables watering at the base level of the plants.This watering system ensures that water does not fall on the leaves or flowers as it leads to disease and scorching problems.

Precision farming is a concept based on observing, testing, measuring and responding to field variability in crops. In this farming, they use research in weathers, test the soil temperature, humidity, growth and moisture. They also rotate crops to improve their diversity and monitor irrigation.

Threshing is the technique used to separate the edible part of crop from the cobs that surrounds it. It is done after harvesting. Soaking is a process in which pulses are kept in water to make them soft. Sprouting is a process in which pulses are kept in wet cloth to receive air and water to sprout. 

Jhoom farming or cultivation is also known as slash and burn agriculture. It is practiced in the areas with thick forest such as Arunachal Pradesh, Meghalaya, Mizoram, etc. In this, a portion of forest is cleared by burning all the trees and weeds in that portion to produce ash. Burnt weeds increase the potash content of the soil and thereby increasing the fertility of the soil. Seeds are dropped on it and maize, chilies, rice, etc are grown.

Jhoom farming or cultivation is also called as slash and burn agriculture. It is practiced in the areas with thick forest such as Arunachal Pradesh, Meghalaya, Mizoram, etc. In this, a portion of forest is cut down and all the trees and weeds are burnt to produce ash. This ash makes that land fertile. Seeds are dropped on it and maize, chilies, rice, etc are grown.

Jhoom farming or cultivation is also known as slash and burn agriculture. It is carried out in the areas with thick forest such as Arunachal Pradesh, Meghalaya, Mizoram, etc. In this, a portion of forest is cut down and all the trees and weeds are burnt to produce ash. This ash makes that land fertile by increasing its potash content. Seeds are dropped on it and maize, chilies, rice, etc are grown.

Bt cotton is the first genetically modified crop of India. This has been developed by MAHYCO (Maharashtra Hybrid Seeds Company) in collaboration with American company, Monsanto.

Slash and burn agriculture is also called as jhum cultivation. It is the process of growing crops in which the land of trees and vegetation are first cleared and then burned thereafter. The burnt soil contains potash which increases the nutrient value of the soil.

The protection of cultivated crop is known as polyhouse farming. In this method, polyethene plastic is used to cover the crops and protect from damage or harms. It is the process which crops extend their lifecycle and production can be done throughout the year.

Polyhouse also known as polytunnels (tunnels made of polyethylene) can be used to provide a higher temperature and humidity than that which is available in the environment but can also protect crops from intense heat, bright sunlight, winds, and hailstones. Capsicum is basically a cool season crop and day temperature less than 30$^o$ celsius is favorable for growth and yield. It can be grown in a polyhouse.

Jhum cultivation which is popularly known as shifting cultivation is one of the oldest types of cultivation practices in India and is practised majorly in the northeastern states of India. This cultivation has a particular pattern that has to be followed according to the cycle or the period of Jhum cultivation.

Slash and burn agriculture is also called as jhum cultivation or shifting cultivation. It is the process of growing crops in which the land of trees and vegetation are first cleared and then burned thereafter. The burnt soil contains potash which increases the nutrient value of the soil. It belongs to category of agroforestry.

(A)Hydroponics is also called as a floating-raft system in which farming is done without using soil on a nutrient-rich solution. For Example, Mint, Tomato, Potato, Lettuce, Basil etc.

• Growing crops in greenhouse produce higher yields due to a lot of reasons like - temperature control, carbon dioxide factor, reduced pest and disease exposure and humidity. 
• The concentrated carbon dioxide results in larger leaves, stronger plant stems and possible early flowering and fruiting.
• So the correct option is 'CO2 enriched atmosphere leads to higher yield'.

Roof gardening is a type of garden which is started on the roof of the building. It is an ideal way of urban gardening.  In urban areas, local and fresh food can be available due to this gardening. To make cities more efficient and to reduce pollution. It reduces heat buildup in cities in the summer season.