Concept:Soil erosion is the removal of topsoil by wind or water. Certain farming practices help protect the soil by keeping it covered and maintaining its structure.Explanation:Crop rotation involves growing different crops in sequence on the same land. This practice reduces soil erosion because different root systems hold the soil together. It also improves soil fertility and structure. Watering, manuring, and irrigation mainly affect moisture and nutrients, not erosion control. Therefore, crop rotation is the most suitable method among the options.Answer:B. crop rotation