Soil erosion is the wearing down of soil. This map provides data on the rate of soil erosion in the United States for a given year. What trend does the map show?
A.
Soil erosion rates are high across the United States.
B.
Soil erosion rates are low across the United States.
C.
Soil erosion rates are uniform across the United States.
D.
Soil erosion rates vary across the United States.