Correct answer: Contour Farming
Contour farming is a sustainable way of farming in which the farmer plant crops perpendicular to the slopes in order to find the contour of a slope of a field. This helps to break up the flow of water and make it harder for soil erosion to take place.
It reduces the fertilizer loss, time and power consumption and it also increases crop yield.
Hence, the correct answer would be Contour Farming.