Fact 1: Echinoderms have a unique water vascular system with tube feet.

Fact 2: Another group of echinoderms are the echinoids.

Given the two facts above, answer the question "What kind of feet do echinoids have?" with the following options: 
- tube
 - long
 - warm
 - webbed
 - arched
 - edible
 - muscle
 - flat


 

 tube        