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 case of acute flaccid paralysis must be observed for how many days for residual weakness \nSelect and explain. \nA. 30 days, B. 42 days, C. 60 days, D. 90 days', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., 60 days", 'role': 'assistant'}]