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': 'Receptor for HIV? \nSelect and explain. \nA. CD4, B. CD3, C. CD5, D. CD56', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) CD4', 'role': 'assistant'}]