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

Fact 2: Muscle spasms are involuntary contractions of a muscle.

Given the two facts above, answer the question "What can muscle spasms cause?" with the following options: 
- massive damage
 - matter vibrating
 - constriction
 - friction
 - Dehydration
 - ketosis
 - stretching
 - photosynthesis


 

   constriction      