How does visualization promote relaxation and stress reduction?
a. it reminds you of other tasks you need to complete.
b. it produces chemicals in your muscles.
c. it enables you to make the world "go away" for awhile.
d. it encourages your friends and family to stay away.

I believe the answer is: c. It enables you to make the world "go away" for awhile.

During the visualisation, you would create a special place in your head that represent the ideal situation which you want to achieve. During stressful situation, this would help you go away from the stress and make your mind enter a state of calmness and relaxation.