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
Fusion inhibitor is? 
Select and explain. 
A. Enfuviide, B. Ritonavir, C. Eirenz, D. Didanosine
A: Enfuviide
Answer: A: Enfuviide 
Explanation: Ans. is 'a' i.e., Enfuviide