One way of representing the structure of an ecosystem is through ecological pyramids. Ecological pyramids represent the amount of organisms, biomass or energy at each tropic level, which most often is in a pyramidal shape. Why are most visual representations of ecosystems in the shape of a pyramid? Select one:
a. Producers use a low amount of sunlight and produce a high amount of energy for all other organisms.
b. Very large carnivores (for example, wolves) have the most energy available to them from the trophic levels below.
c. The large number of primary consumers supplies a large amount of energy for fewer autotrophs.
d. At each trophic level, energy is lost (as heat) in the transfer of energy from one trophic level to another.