Let's think step by step! What relaxes, thereby causing aneurysms?
Options:
- (A) layers of fat
- (B) Veins and arteries.
- (C) sweating
- (D) matter vibrating
- (E) blood vessels
- (F) the skin
- (G) Chemical energy
- (H) sensory neurons
The thinking starts now:
Dilation occurs when cell walls relax. An aneurysm is a dilation of a blood vessel. Aneurysms are caused by relaxation of cell walls of blood vessels. The final answer: (E).