Scientists Know Relatively Little About the Roles of Most Soil

Multiple Choice

Scientists know relatively little about the roles of most soil organisms because

A) very few soil organisms have been identified
B) it is hard to study them in a natural environment
C) they are too small to see, even with high-powered microscopes
D) they do not affect soil much and are not worth studying
E) none of these; scientists have a good understanding of most soil organisms