All of the following are potential effects of clearing land except a. less biodiversity b. less arable land c. more co2 emissions d. more erosion

The correct answer is B. Less arable land.
Arable land is the main reason why the land is cleared. Arable land is the land that is suitable for ploughing and of sufficient quality for growing plants. So for this reason, the forests are cleared (by cutting the trees and bushes) and more land for agriculture is gained.

D. i believe that doesn't even exist.