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: Unknown
[{'content': 'A man had Egg omelet 1-4 hours back and developed diarrhea, vomiting and abdominal cramps. Most likely cause of poisoning. \nSelect and explain. \nA. Staphylocoocus, B. Salmonella, C. Bacillus cereus, D. Clostridium', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]