This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti-HIV Drugs, Subject name: Pharmacology
Nucleoside reverse transcriptase inhibiting drug, which is a guanosine analogue is:- 
Select and explain. 
A. Ritonavir, B. Zidovudine, C. Abacavir, D. Acyclovir
C: Abacavir
Answer: C: Abacavir 
Explanation: NI ANALOGUE OF Zidovudine Thymidine Stavudine Thymidine Lamivudine Cytosine Emtricitabine Cytosine Zalcitabine Cytosine Tenofovir Adenosine Didanosine Adenosine Abacavir Guanosine