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': 'Which among the following anti-HIV drugs is an inhibitor of viral fusion? \nSelect and explain. \nA. Enfuvirtide, B. Nelfinavir, C. Efavirenz, D. Etanercept', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]