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': 'The usual incubation period for typhoid fever is \nSelect and explain. \nA. 3-5 days, B. 21-25 days, C. 10-14 days, D. less then 3 days', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]