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
[{'content': 'Drug of choice for myasthenia gravis - \nSelect and explain. \nA. Gallamine, B. Succinylocholine, C. D. tubocurare, D. Pyridostigmine.', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]