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': 'Which of the following is false regarding point source single exposure epidemic? \nSelect and explain. \nA. Often explosive, B. Is caused by infectious agents only, C. Cases develop within incubation period only, D. Rapid rise and fall of epidemic curve occurs', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Point source single epidemic is commonly caused by infectious agent but not always. The example of non infectious agents being involved include Bhopal gas tragedy, Chernobyl tragedy etc. Ref: Park, 21st Edition, Pages 60, 61.', 'role': 'assistant'}]