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': 'Shortest incubation period is seen in- \nSelect and explain. \nA. Influenza, B. Hepatitis B, C. Hepatitis A, D. Rubella', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Mumps\xa0→\xa016 - 18 days\nInfluenza\xa0→\xa02 - 3 days\nHepatitis A\xa0→\xa015 - 90 days\nHepatitis B\xa0→ \xa06 wk to 6 months', 'role': 'assistant'}]