OCD obsessions vs compulsions: BEST describes obsessions:

• A. Repetitive behaviors performed in response to obsessions.
• B. Obessions are mood disturbances.
• C. Obsessions are intrusive thoughts.
• D. A cognitive bias toward optimism.

Answer: (C)

The idea being tested is what obsessions in OCD look like. Obsessions are persistent, intrusive, unwanted thoughts, images, or urges that pop into consciousness and cause considerable distress. They are experienced as involuntary and often feel alien or irrational, yet the person can’t easily shake them off. This is why they’re described as intrusive thoughts.

The other descriptions don’t fit obsessions: repetitive behaviors done in response to fears or urges are compulsions—actions meant to reduce the distress caused by obsessions. Obsessions aren’t mood disturbances; they’re cognitive intrusions, not mood states. And a cognitive bias toward optimism isn’t a defining feature of OCD obsessions.