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': 'A male child of 15 years with a mental age of 9 years has an IQ off – \nSelect and explain. \nA. 50, B. 60, C. 70, D. 80', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]