Fact 1: Bivalves feed on plankton and nonliving organic matter.

Fact 2: Bivalved arthropods are especially common.

Given the two facts above, answer the question "what do arthropods feed on?" with the following options: 
- spiders
 - rocks
 - seeds
 - water
 - pollen
 - plankton
 - barnacles
 - food


 

      plankton   