What is the main cause of increased erosion

The main cause of increased erosion is natural elements like rain, wind and ice. Erosion is the process by which the surface of the Earth gets worn down. 
Soil erosion is also a big thing, it is caused by mostly rain that contributes to floods. This stuff is bad for farmers because they do a lot of farming and with erosion increasing the growing crops are decreasing because of erosion. 

The answer is c) pyrite