This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Anatomy
Resistance to acyclovir is most commonly due to mutation in the viral gene that encodes a protein that 
Select and explain. 
A. Conves viral RNA into DNA, B. Phosphorylates acyclovir, C. Transpos acyclovir into the cell, D. Transpos acyclovir out of the cell
B: Phosphorylates acyclovir
Answer: B: Phosphorylates acyclovir 
Explanation: Ref-KDT 6/e p768 Nucleoside/tide analogues act by conveing to NTPs. First phosphorylation step occurs inside the virus and resistance occurs if there is mutation in this gene