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': 'Mental retardation is defined if IQ is below ? \nSelect and explain. \nA. 90, B. 80, C. 70, D. 60', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is `c' i.e., 70 o A child with IQ . 70 is called mentally retarded.", 'role': 'assistant'}]