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': 'Culture media used for diagnosis of EHEC O157:H7 \nSelect and explain. \nA. O culture, B. Sorbitol macconkey agar, C. XLD agar, D. Deoxycholate media', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]