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: Medicine
[{'content': 'Usual incubation period for hepatitis B virus infection is: \nSelect and explain. \nA. 1 — 2 days, B. 1 — 2 weeks, C. 1 — 6 months, D. 1 year', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]