Mr. Green wants to teach his students about an interaction between Earth's biosphere and geosphere. Mr. Green had his students collect soil samples from various areas of the school campus. The students noticed that the upper layer of the soil in

the wooded area of the campus was darker than the upper layer of the sandy playing field. Why would there be a difference in

color in the upper layer of the two soil samples?

A. The soil in the wooded area was made primarily of organic matter and not rock particles

B. The soil in the wooded area was made primarily of rock particles and not organic matter.

c. There is less erosion on the playing field due to fewer plants growing on the field.

D. There is more erosion in the wooded area due to more plants growing in the area,