Answer:
(a) Crop rotation.
Step-by-step explanation:
Crop rotation is the rotational cultivation of crops one after another in the same field or area. This means that different crops are cultivated in sequence, one after the other, on a rotational basis.
Crop rotation is one way of maintaining the nutrients of the soil. It also allows for the production of different crops without the need to move from one place to another. Crop rotation also helps in growing seasonal crops, thereby making crop production stable, providing a constant supply of crops for the farmers.
Thus, the correct answer is option a.