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
[{'content': 'The following drug acts by blocking reverse transcriptase \nSelect and explain. \nA. Zidovudine, B. Acyclovir, C. Amantadine, D. Ribavirin', 'role': 'user'}, {'content': 'Answer: A \nExplanation: 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', 'role': 'assistant'}]