Describe the process of weathering

there are two processes of weathering the first process is natural weathering which is when rain erodes away rocks and other things example when rocks are tumbling in a stream of water and continuously being hit against other rocks, is a form of natural weathering.  the other form is chemical weathering which is when chemicals erode away rocks and the surface of the earth, acid rain is a example of chemical weathering.

Explanation:

d is the logical answer but im not a 100% sure