The correct answer is: d) All of the above.
Contour farming is a method of farming that involves planting crops in rows that follow the natural contours of the land. This helps to prevent soil erosion by reducing the amount of water that runs off the land.
Terracing is a method of farming that involves creating a series of level platforms on a hillside. This helps to reduce the amount of soil erosion by preventing water from running off the land.
Agroforestry is a system of farming that combines the cultivation of crops with the raising of trees. This helps to prevent soil erosion by providing a root system that helps to hold the soil in place.
All of these methods are traditional soil conservation practices in Kerala.