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: Social & Preventive Medicine
[{'content': 'Chronological age 10yrs, mental age 4yrs. What that person called as? \nSelect and explain. \nA. Idiot, B. Imbecile, C. Normal, D. Genius', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Imbecile", 'role': 'assistant'}]