Which of the following is incorrect for a pyramid of productivity?

• A. Only about 10% of the energy in one trophic level is passed into the next level.
• B. Because of the loss of energy at each trophic level, most food chains are limited to three to five steps.
• C. The pyramid of productivity of some aquatic ecosystems is inverted because of the large zooplankton primary - consumer level.
• D. Eating grain-fed beef is an inefficient means of obtaining the energy trapped by photosynthesis.