Fact 1: Dilation occurs when cell walls relax.

Fact 2: Blood flow is improved by vitamin E and it causes blood vessels to dilate or expand.

Given the two facts above, answer the question "What happens when cell walls relax?" with the following options: 
- evaporation
 - permineralization
 - preventing heat transfer
 - allow growth
 - it keeps an organism warm
 - air cools
 - Cell walls expand
 - heat produced


 

       Cell walls expand  