D. decrease the amount of erosion along the hillside
Explanation:
When logging operations are conducted on a hillside near a river, the operations will decrease the amount of erosion along the hillside because the tree's root hold soil particles and does not allow them to erosion. We can see in many region that there is presence of vegetation on the bank of river or stream in order to prevent erosion of soil so that's why we can say that logging operations causes decrease erosion along hillside.
