The Degree of Erosion in the United States Is Best

The degree of erosion in the United States is best described by the following statement.

A) There is a set amount of soil that was originally formed and erosion continually removes some of it; therefore,we will one day run out of topsoil due to erosion.
B) Farmland soil is eroding faster than it is being formed.
C) Removal of trees helps build up topsoil and prevents erosion.
D) Soil forms at generally the same rate as soil erodes,so there is an overall balance just as worldwide precipitation equals evaporation; it is just not evenly spread across the landscape.