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': 'Child survival index is calculated by ? \nSelect and explain. \nA. 1000-IMR/10, B. IMR-1000/10, C. 1000-U5MR/10, D. 1.15MR-1000/10', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., 1000-U5MR", 'role': 'assistant'}]