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: Pharmacology
[{'content': 'The HIV fusion inhibitor, enfuvirtide, acts at the site \nSelect and explain. \nA. Gp 120, B. Gp 41, C. P24, D. CXCR4', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]