You are presented with the question "What kind of feet do echinoids have?" and the following answer choices: 
- tube
 - long
 - warm
 - webbed
 - arched
 - edible
 - muscle
 - flat

Now knowing that echinoderms have a unique water vascular system with tube feet and another group of echinoderms are the echinoids, choose the best answer.


 

 tube        