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: Microbiology
[{'content': 'Incubation period for bacillus cereus -a) 1-6 hrsb) 8-16 hrsc) 24hrsd) > 24 hrs \nSelect and explain. \nA. ac, B. bc, C. ad, D. ab', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]