This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology, Subject name: Microbiology
The following drug acts by blocking reverse transcriptase 
Select and explain. 
A. Zidovudine, B. Acyclovir, C. Amantadine, D. Ribavirin
A: Zidovudine
Answer: A: Zidovudine 
Explanation: Zidovudine acts by inhibiting the conversion of RNA to DNA by blocking the enzyme reverse transcriptase. It is a prodrug which has to be conveed to triphosphate form to be active Baveja 5th ed Pg.: 519