Which of the following best explains the natural cause of a decrease in biomass as succession peaks in a climax community? Select one:

AOnce a climax community is reached, there are no nutrients left in the ecosystem to support the growth of plants.

BThe canopy of forests prevents sufficient light from reaching the forest floor, thereby limiting primary productivity.

CHumans usually cut down old growth forests.

DThe presence of large animals such as elk or wolves prevents the development of young animals.