Which of the Following Is Primarily Responsible for Limiting the Number

Multiple Choice

Which of the following is primarily responsible for limiting the number of trophic levels in most ecosystems?

A) Many primary and higher-order consumers are opportunistic feeders.
B) Decomposers compete with higher-order consumers for nutrients and energy.
C) Nutrient cycling rates tend to be limited by decomposition.
D) Energy transfer between trophic levels is usually less than 20 percent efficient.