Fact 1: Constriction occurs when the muscular walls of blood vessels contract.

Fact 2: Arteries and veins are blood vessels.

Given the two facts above, answer the question "What happens when muscular walls of arteries and veins contract?" with the following options: 
- connection
 - It expands
 - Dehydration
 - construction
 - forces
 - massive damage
 - constriction
 - contraction


 

       constriction  