The correct answer is: C. by water erosion.
Crop rotation is a system of farming where different types of crops are grown in the same field in a planned sequence. This helps to prevent the loss of topsoil, which can be caused by water erosion. When the same crop is grown in the same field year after year, the soil can become depleted of nutrients and more susceptible to erosion. Crop rotation helps to replenish the nutrients in the soil and also helps to break up the soil, which makes it less likely to be eroded by water.
Option A: Weathering is the process of breaking down rocks and minerals by the action of wind, water, and ice. Crop rotation does not help to prevent weathering.
Option B: Wind erosion is the process of soil being blown away by the wind. Crop rotation can help to prevent wind erosion by breaking up the soil and creating a barrier between the soil and the wind.
Option D: The loss of mineral content in the soil is not a major concern with crop rotation. Crop rotation helps to replenish the nutrients in the soil, which helps to prevent the loss of mineral content.