What are two processes that must occur to form soil?

A. weathering breaks rocks into minerals and plants die and decay.

B. erosion and weathering

C. Plants produce loam and plants produce humus

D. Erosion transports mineral particles and plants die and decay

To form soil, the two processes which must occur are erosion and weathering, so the correct answer here is B. Soil formation is a continuous process, but also one which takes a long time. It can sometimes more than five hundred years for 1cm of soil to form.