Hint: methane gas is formed as a result of the anaerobic decomposition of organic matter in the soils that have abundance of methanogenic bacteria.
Complete Step-by-Step Solution:
In order to understand which agricultural field that produces the maximum methane gas into the atmosphere, we need to understand how farming takes place in the first place.
Any sort of farming is basically done on some form of soil. Depending on the type of soil used, the crop to be grown can be decided. This is because, each type of crop has its own needs or necessities for the various nutrients present in the soil, along with the availability of water. The crops thrive on the nutrients it absorbs from the soil as well the air around it. To overcome such problems, crops come up with their own defence mechanisms.
One such crop is rice. Rice is grown in fields that are filled with water. This causes the soil to be forever covered in water and causes a lack of availability of oxygen. To overcome this problem, the crops allow certain bacteria to cultivate. These bacteria decompose organic matter to produce the necessary nutrients for the crop. One of the end products obtained from this decomposition is methane, which is continuously diffused into the atmosphere by the rice crop.
Rice crops are grown on paddy fields. Hence, the agricultural field that produces the maximum methane gas into the atmosphere is paddy field.
Hence, Option B is the correct option.
Note: similar to rice crops, different plants develop various such mechanisms to ensure their survival. But the methane produced by the rice crops is really harmful for the planet as it is a green gas and can accelerate global warming.