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: Medicine
Drug of choice for cytomegalovirus - 
Select and explain. 
A. Acyclovir, B. Amantadine, C. Ganciclovir, D. Idoxuridien
C: Ganciclovir
Answer: C: Ganciclovir 
Explanation: None