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
[{'content': 'A person has recurrent intrusive thoughts which he thinks are irrational and wants to stop is: MAHA 12 \nSelect and explain. \nA. Compulsion, B. Obsession, C. Delusion, D. Hallucination', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. Obsession', 'role': 'assistant'}]