<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 25-year-old sexually active male presents to an internal medicine physician for a routine health check up after having several unprotected sexual encounters. After appropriate testing the physician discusses with the patient that he is HIV and must be started on anti-retroviral treatment. Which of the following medications prescribed acts on the gp41 subunit of the HIV envelope glycoprotein?? A: Amantadine, B: Rimantadine, C: Zidovudine, D: Saquinavir, E: Enfuvirtide,  <response>: This is a question about HIV treatment. The key information in the question stem is that the patient is HIV and needs to start anti-retroviral treatment. The question asks which medication acts on the gp41 subunit of the HIV envelope glycoprotein. Looking at the choices, Amantadine and Rimantadine are antiviral drugs used for influenza, not HIV. Zidovudine is a nucleoside reverse transcriptase inhibitor used in HIV treatment, but does not target gp41. Saquinavir is a protease inhibitor used for HIV, but also does not target gp41. By process of elimination, the answer must be Enfuvirtide, which is a fusion inhibitor that binds to gp41 and prevents HIV from fusing with and entering host cells.E: Enfuvirtide 