Which of the following best describes energy availability in higher trophic levels?

Energy availability decreases at higher trophic levels due to the inefficiency of energy transfer in food chains and food webs. When energy is transferred from one trophic level to the next, only about 10% of the energy from the lower level is typically passed on to the higher level. This phenomenon, known as the "10% rule," occurs because much of the energy is lost through metabolic processes as heat, used for movement, respiration, and reproduction, or is not consumed by the next level (as it may be indigestible).

As a result, as you move up the trophic levels—from producers to primary consumers to secondary consumers and so forth—there is a reduction in the total energy available to organisms. This explains why higher trophic levels have less energy available compared to lower levels, contributing to smaller populations of predators at the top levels of food chains. Consequently, energy availability is indeed decreased at higher trophic levels.