Some crustaceans feed on\nOptions:\n- (A) phytoplankton\n- (B) fungi\n- (C) refraction of light\n- (D) heat energy\n- (E) an organism's body\n- (F) carbon\n- (G) algae\n- (H) salt and water.
Step-by-step reasoning process below:
(A)
Zooplankton are tiny animals that feed on phytoplankton.

Many zooplankton are crustaceans.

Some crustaceans feed on phytoplankton.

.

The answer: (A)