You are presented with the quiz "An animal which may have one or two hearts to pump blood is:" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "mollusks have a circulatory system with one or two hearts that pump blood" and "interestingly, a squid is also a mollusk". 

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


 

 squid          