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': 'Incubation period less than few hours \nSelect and explain. \nA. Food poisoning, B. Hepatitis A, C. Influenza, D. Rabies', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Incubation period of food poisonings:\nFood poisoning - Incubation period\nSalmonella -\xa012 – 24 hours\nStaphylococcal -\xa01 – 6 hours\nBotulism -\xa012 – 36 hours\xa0\nCl. perfirengens -\xa06 – 24 hours\nB. cereus (emetic form) -\xa01 – 6 hours\nB. cereus (diarrhoel form) -\xa012 – 24 hours', 'role': 'assistant'}]