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
Only nitrate not undergoing first pass metabolism is 
Select and explain. 
A. Nitroglycerin, B. Isosorbide dinitrate, C. Isosorbide mononitrate, D. None of the above
C: Isosorbide mononitrate
Answer: C: Isosorbide mononitrate 
Explanation: Isosorbide mononitrate does not undergo first pass metabolism.