Need ! will mark ! which event occurs after erosion of earth’s surface? a. surface material breaks down into smaller pieces. b. very dense particles settle faster than low-density particles. c. large particles are carried away to a new location by ice and glaciers. d. round particles form new landforms more slowly than flat particles do.

I would have to say "Surface material breaks down into smaller pieces" or option A. Erosion is the breaking down of rock using compaction, weathering, water, wind, etc... anything that can break down a rock into smaller pieces. So in this case if erosion takes place on the surface of the Earth also known as the crust then it would break down into smaller pieces. 

Hope this helps!

Could you elaborate?