This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Forensic Medicine
A 15-year-old boy feels that the di has hung onto him whenever he passes through the diy street. He knows that there is actually no such thing after he has cleaned once, but he is not satisfied and is compelled to think so. The most likely diagnosis is:Gujarat 07 
Select and explain. 
A. OCD, B. Conduct disorder, C. Agoraphobia, D. Adjustment disorder
A: OCD
Answer: A: OCD 
Explanation: Ans. OCD