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: Psychiatry
[{'content': 'Most common presentation of obsessive compulsive disorder in adult is \nSelect and explain. \nA. Symmetry, B. Sexual thoughts, C. Pathological doubt, D. Aggression', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Most common OCD is about contamination followed by pathological doubt.', 'role': 'assistant'}]