Answer:
c. Compulsion
Explanation:
Compulsion comes from the word compelled, meaning "force or oblige (someone) to do something." A compulsion is the need to do or behave in an irrational way because there is something in your mind compelling you to do it. In the case of many people with OCD, this is often some sort of threat, i.e. if they don't do a task a family member will die.
