This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti Microbial, Subject name: Pharmacology
Which of the following is a reverse transcriptase inhibitor? 
Select and explain. 
A. Ritonavir, B. Saquanavir, C. Amprenavir, D. Tenofovir
D: Tenofovir
Answer: D: Tenofovir 
Explanation: ANSWER: (D) TenofovirREF: Harrison 17th ed chapter 182Class of antiretroviral drugs for hivExampleReverse Transcriptase Inhibitors ( NRTI - nucleoside reverse transcriptase inhibitors)ZidovudinefAZT), Didanosine(DDl), zalcitabine(DDc) , Sfavudine (d4T), Lamivudine{3TC) , AbacavirReverse Transcriptase Inhibitors ( NNRTI - Non nucleoside reverse transcriptase inhibitors)Emtricitabine (FTC),tenofovir, delavirdine , efavirenzProtease inhibitorsRitonavir , saquanavir , amprenavir , lopinavir , nelfinavir , indinavirIntegrase InhibitorRaltegravirEntry InhibitorsEnfuvirtide