Question

organisms at the bottom of the pyramid produce enough usable chemical energy to support the entire ecosystem through
a predation.
b photosynthesis.
c cell respiration.
d anaerobic respiration.

Explanation:

The bottom of the pyramid shows phytoplankton, which are autotrophs. Autotrophs produce usable chemical energy via photosynthesis, converting sunlight into glucose (chemical energy) to support the entire ecosystem. Predation transfers energy, while cell/anaerobic respiration releases energy, not produces it for the ecosystem.

Answer:

B. photosynthesis.