You are presented with the quiz "What do earthworms ingest in order to form and enrich soil?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "earthworms are important deposit feeders that help form and enrich soil" and "deposit feeders ingest sediment and then extract the food". 

So, what's the best answer to the question?


 

   sediment        