Obsessive-Compulsive Disorder (OCD) is described as:

• A. A fear of dark rooms
• B. The use of threats or physical force to intimidate others
• C. Obsessive-Compulsive Disorder (OCD) is defined as a disorder characterized by unwanted repetitive thoughts and/or actions
• D. A prolonged feeling of helplessness, hopelessness, and sadness

Answer: (C)

OCD is an anxiety-related condition defined by intrusive, unwanted thoughts (obsessions) and repeative behaviors or mental acts (compulsions) that a person feels driven to perform to reduce the distress those thoughts cause. These obsessions and compulsions are typically time-consuming and cause significant impairment in daily life, beyond occasional neatness or worry.

This description fits OCD much more than the other scenarios. A fear of dark rooms is a specific phobia, not OCD. Using threats or physical force to intimidate others describes aggression or coercive behavior, not a mental health pattern of obsessive thoughts and compulsive acts. A prolonged feeling of helplessness, hopelessness, and sadness characterizes depression, not OCD.