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': 'Obsession is a disorder of: MP 09 \nSelect and explain. \nA. Perception, B. Thinking, C. Memory, D. Judgment', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. Thinking', 'role': 'assistant'}]