The echinoids
A)have five long,slender arms.
B)are enclosed in an endoskeletal test or shell.
C)lack tube feet.
D)lack ambulacral areas.
E)are unable to move because of their spines.

Question

Quizplus · Accepted Answer

Echinoids are enclosed in an endoskeletal test or shell, which protects their internal organs and forms the basis for their spines.

Answer: D
 Echinoids have ambulacral areas, which are rows of tube feet used for locomotion and feeding.

The Echinoids