Which of the following anti-HIV medications acts by blocking the fusion of the virus with host cells?

Explanation

Enfuvirtide is an HIV drug that prevents the virus from fusing with the host cell membrane, thereby blocking viral entry. Nelfinavir is a protease inhibitor, Efavirenz is a non-nucleoside reverse transcriptase inhibitor, Etanercept is unrelated to HIV treatment, and Raltegravir is an integrase inhibitor.