Dilation occurs when part of a cell that a what does not have relaxes.
Options:
- (A) breathing
- (B) organ
- (C) the eyes
- (D) abrasion
- (E) complex
- (F) animal
- (G) nerves
- (H) retina OK. Let's think hard:
Dilation occurs when cell walls relax. Animals have no cell walls. Dilation occurs when part of a cell that an animal does not have relaxes.
So, the final answer is (F).