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': 'CD4 count in normal healthy adult is \nSelect and explain. \nA. 500, B. 200, C. 1000, D. 300', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]