You are presented with the quiz "Marine annelids can make a swimming larvae called what?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "adult worms go through a major transformation to develop reproductive organs" and "marine annelid worms have larvae called trochophores that swim about by means of cilia". 

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


 

      a trochophore     