This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
Which drug is used for topical application in respiratory papillomatosis? 
Select and explain. 
A. Acyclovir, B. Ranitidine, C. Cidofovir, D. Ribavirin
C: Cidofovir
Answer: C: Cidofovir 
Explanation: Cidofovir Gold standard treatment for respiratory papillomatosis is Laser MLS/ Powered MLS (using microdebrider). Cidofovir is a recent drug which is used intralesionally or topically. Its active metabolite, cidofovir diphosphate, inhibits viral replication by selectively inhibiting viral DNA polymerase.