This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti-HIV Drugs, Subject name: Pharmacology
Which of the following binds to viral envelope glycoprotein preventing the conformational changes required for the fusion of viral and cellular membranes? 
Select and explain. 
A. Abacavir, B. Indinavir, C. Enfuviide, D. Oseltamivir
C: Enfuviide
Answer: C: Enfuviide 
Explanation: Enfuviide is a fusion inhibitor useful in the treatment of HIV infections. It acts by binding to HIV-I envelope transmembrane glycoprotein (gp41) which is involved in fusion of viral and cellular membranes. Abacavir is a NI Indinavir is a protease inhibitor Oseltamivir is a neuramindase inhibitor.