This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'Resistance to zidovudine develops due to : \nSelect and explain. \nA. Mutation at reverse transcriptase, B. Increased efflux of the drug from inside the cell, C. Increased metabolism of the drug, D. Decreased zidovudine 5 triphosphate formation', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]