You are presented with the question "What is an example of an echinoderm?" and the following answer choices: 
- a fish
 - eel
 - starfish
 - parasites
 - ferns
 - shark
 - fertile
 - algae

Now knowing that echinoderms have a unique water vascular system with tube feet and each starfish arm is lined with tube feet, choose the best answer.


 

   starfish      