You are presented with the question "What feed on plankton and nonliving organic matter?" and the following answer choices: 
- mussels
 - sea lions
 - sharks
 - phytoplankton
 - animals
 - fungi
 - barnacles
 - polar bears

Now knowing that bivalves feed on plankton and nonliving organic matter and mussels are bivalve mollusks, choose the best answer.


 

 mussels        