You are presented with the quiz "a connection is between the eye and what type of  feet in echinoderms" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "echinoderms have a unique water vascular system with tube feet" and "another obvious connection between the eye and the rest of the body is the vascular system". 

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


 

 tube          