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
Which of the following has poorest oral bioavailability? 
Select and explain. 
A. Oseltamiviir, B. Zanamivir, C. Rrimanti dine, D. Amantadine
B: Zanamivir
Answer: B: Zanamivir 
Explanation: Ans. is 'b' i.e., Zanamivir o Zanamivir has minimum oral bioavailability thus it is given by intranasal or intravenous routes.