Options are: (1). barnacles (2). mollusks (3). animals (4). the Sun (5). sharks (6). graptolites (7). bacteria (8). dogs
Given those answer options, answer the question: You are presented with the quiz "What feeds on plankton and nonliving organic matter?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "bivalves feed on plankton and nonliving organic matter" and "mussels are bivalve mollusks". So, what's the best answer to the question?
A:
(2).