Ans. is 'a' i.e., Raltegravir New drugs in HIV infectiono Etravirine is recently approved NNRTI. This is second generation NNRTI and is effective against HIV resistant to first generation NNRTI (Efavirenz, Delaviridine. Nevirapine).Fusion inhibitors (Entry inhibitors)o Enfluvtritide binds to Gp41 subunit of HIV envelop protein and inhibits the fusion of viral and host cell membrane.o Maraviroc is a CCR5 Co-receptor antagonist and is only active against "CCR - 5 - tropic virus" which tends to predominate early in infection.Integrase inhibitorso Raltegravir and Elvitegravir act by inhibiting enzyme integrase.