Where does a starfish have its water vascular system?\nOptions:\n- (A) salt and water.\n- (B) Chlorophyll\n- (C) the environment\n- (D) in its arms\n- (E) on the rocks\n- (F) in its eyes\n- (G) Epidermis\n- (H) in the ocean
Please answer and provide answer explanation.
(D)
Echinoderms have a unique water vascular system with tube feet.

Each starfish arm is lined with tube feet.

Each starfish arm contains part of the water vascular system.

.

So, the final answer is (D)