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
All aggravates myastheia gravis,except ? 
Select and explain. 
A. Azathioprine, B. Quinidine, C. Tetracycline, D. Aminoglycoside
A: Azathioprine
Answer: A: Azathioprine 
Explanation: Ans. is 'a' i.e., Azathioprine o Tetracycline, aminoglycoside and quinidine can aggravate mysthenia gravis.