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': 'Incubation period for hepatitis A : \nSelect and explain. \nA. 2-6 weeks, B. 12 weeks, C. 8 weeks, D. 10 weeks.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]