The correct answer is option 2, which includes contour bunding and regulation of land use as the remedies to soil erosion.

Contour bunding is a method where bunds or ridges are built along the contour lines of a slope to slow down the flow of water and prevent it from eroding the soil. This helps to retain moisture and reduce erosion.

Regulation of land use involves controlling how land is used and managed. This includes practices such as proper crop rotation, avoiding overgrazing, and implementing conservation measures like terracing or planting cover crops. By regulating land use, erosion can be minimized and soil health can be maintained.

Option 1 (I, III) is incorrect because it includes cutting of trees as a remedy, which is not an effective solution as trees help to stabilize the soil and prevent erosion. Option 3 (III, IV) and option 4 (II, III) are also incorrect.