Which of the following is not a major source of pressure that influences teens to seek escape through drug abuse?
a. family demands and expectations
b. a supportive network of friends
c. difficult school assignments
d. stressful jobs and activities

A supportive network of friends is not a major source of pressure that influences teens to seek escape through drug abuse, instead it provides relief and support against problems. So the right answer is  B.

What isn't a major source of pressure which influences teens to seek escape through drug abuse would be a supportive network of friends. On the contrary, a supportive network of friends would likely act very much against someone from their group taking up drugs or similar things.  

Aand b would both be correct

Can you give answer choices?