<prompt> Which of the following is a protease inhibitor -AbacavirZidovudinRitonavirEnfuvirtide  <response>: Ans. is c i.e., Ritonavir Antiretroviral drugsa Nucleoside reverse transcriptase inhibitors NRTIs -Zidovudin, Didanosine, Zalcitabine, Stavudine, Lamivudine, Abacavir.b Nucleotide reverse transcriptase inhibitor - Tenofovirc Nonucleoside reverse transcriptase inhibitors NNRTIS - Nevirapine, Efavirenz, Delavirdine, Etravirine Rilpivirine.d Protease inhibitors - Ritonavir, Indinavir, Nelfinavir, Saquinavir, amprenavir, Lopinavir, Fosamprenavir, Atazanavir, Darunavir, Tipranavir.e Fusion inhibitor - Enfuvirtide, Maraviroc.f Integrase inhibitors - Roltegravir, Elvitegravir. 