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
Anti-influenza drug which is/are given through inhalation route ? 
Select and explain. 
A. Amantadine, B. Oseltamivir, C. Zanamivir, D. Rimantadine
C: Zanamivir
Answer: C: Zanamivir 
Explanation: Ans. C. ZanamivirAnti-influenza drugsAmantadine, rimantadine, oseltamivir and zanamivir.Only zanamivir is given by parenteral route (intranasd or intravenous). all others are given orally.Zanamivir has lowest oral bioavailability lowest t1/2 (shoest acting).Rimantadine has maximum plasma protein binding, while oseltamivir has minimum plasma protein binding.Rimantadine has maximum metabolism.