<span>Commensalism is an interaction in which one of those species would benefit, and the other one would not be affected. Parasitism is an interaction in which one of those species would benefit at the expense of the host organism. Thus, in commensalism we have one positive and one neutral result while in parasitism we have one positive and one negative result.</span>
Answer: C. The C horizon is very deep.
Horizons are the layers of soil develops as a result of soil formation. Horizon lies parallel to the earth surface. Each horizon differs from the other on the basis of amount or organic matter present, color of the soil, texture of soil and other components making up horizon, and amount and type of minerals present in the soil.
C horizon is the horizon that lies deeper region of the collective soil horizon. It consist of unweathered or partially weathered rocks or their aggregates. Therefore, it retains the original chemical composition of the parent rock. This results in the higher mineral content as compared to other horizons. This horizon also lacks the organic matter as no or very little decomposition activity of plant and animal matter takes place. Therefore, color of soil in this horizon in the absence of organic matter remains light.
Hence, a sample of soil from a C horizon is light brown in color and has a high content of a mineral called feldspar is because of the fact that the C horizon is very deep.
