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 drugs has been used in the treatment of angina by inhalation and has a very rapid onset and brief duration of action ? 
Select and explain. 
A. Amyl nitrite, B. Isosorbide mononitrate, C. Nitroglycerine, D. Propranolol
A: Amyl nitrite
Answer: A: Amyl nitrite 
Explanation: None