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': 'True about point source epidemic are all except - \nSelect and explain. \nA. The curve has rapid rise and slow decline, B. All cases occur in one incubation period, C. One single peak only, D. No secondary curves', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Epidemic curve of point source epidemic has -\n\nRapid rise\xa0\xa0\xa0\xa0\nRapid fall\xa0\xa0\nNo secondary wave', 'role': 'assistant'}]