Fact 1: Dilation occurs when cell walls relax.

Fact 2: An aneurysm is a dilation, or bubble, that occurs in the wall of an artery.

Given the two facts above, answer the question "what can be relaxed by dilation?" with the following options: 
- artery
 - alveoli
 - the eyes
 - the skin
 - nerves
 - sweating
 - epidermal
 - breathing


 

 artery        