You are presented with the question "Some crustaceans feed on" and the following answer choices: 
- phytoplankton
 - fungi
 - refraction of light
 - heat energy
 - an organism's body
 - carbon
 - algae
 - salt and water.

Now knowing that zooplankton are tiny animals that feed on phytoplankton and many zooplankton are crustaceans, choose the best answer.


 

 phytoplankton        