This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Social science, Mental health & Genetics, Subject name: Social & Preventive Medicine
[{'content': 'A male child of 15 years with a mental age of 12 years has an IQ of - \nSelect and explain. \nA. 50, B. 60, C. 70, D. 80', 'role': 'user'}, {'content': "Answer: D \nExplanation: IQ = mental age/chronological age *100 mental age is 12 yr, chronological age is 15 yr so 12/15 =0.8, 0.8*100= 80 ref; (page no;637) 25th edition of PARK's textbook of Preventive and Social medicine", 'role': 'assistant'}]