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: Medicine
Drug of choice for myasthenia gravis - 
Select and explain. 
A. Gallamine, B. Succinylocholine, C. D. tubocurare, D. Pyridostigmine.
D: Pyridostigmine.
Answer: D: Pyridostigmine. 
Explanation: None