Cynthia’s psychology professor asks the class not to think about purple unicorns. Though Cynthia has never once before thought abouta purple unicorn, she finds that she cannot stop thinking about them. Cynthia is experiencing as a result of her attempts at .
a. the rebound effect; ruminationthe
b. rebound effect; thought suppression
c. distraction; rumination
d. distraction; thought suppression

Cynthia is experiencing b. rebound effect as a result of her attempts at thought suppression.

Explanation:

Thought suppression is the conscious, motivated way of trying to erase or remove a certain thought. This conscious activity often leads to the rebound effect, which creates the opposite outcome; the individual will most likely keep thinking about this specific thought.

In this case, Cynthia's conscious act of trying not to think about a purple unicorn, leads to the rebound effect, in which she cannot stop thinking about it.

i would say b. research typically uses a variety of sources