The diagram is a model of an energy pyramid of an ecosystem. Primary producers are modeled by a wide rectangle labeled 100 percent. Above them are first-level consumers and a narrow rectangle labeled 10 percent. Then second level consumers at 1 percent, and on top the third-level consumers at 0.1 percent.

The levels of the diagram are labeled with percentages. What do the percentages represent?

A. the average energy requirement of organisms in each trophic level
B. the relative amounts of energy contained by the organisms in each trophic level
C. the energy lost as heat from one trophic level to the next
D. the rate of conversion of light energy to chemical energy