This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology, Subject name: Microbiology
[{'content': 'Transmission of hepatitis A virus occurs - \nSelect and explain. \nA. one week before and one week after onset of symptom, B. 2 weeks before onset of symptoms, C. 2 weeks after onset of symptoms, D. 1 week after onset of symptoms', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The viruses shed in feces during the late incubation period and prodromal phase of illness REF:ANANTHANARAYANAN TTEXTBOOKOF MICROBIOLOGY 9EDITION PGNO.541', 'role': 'assistant'}]