This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
[{'content': 'Drug used in ameliorative test for myasthenia gravis is \nSelect and explain. \nA. d-TC, B. Edrophonium, C. Pyridostigmine, D. Tacrine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: .', 'role': 'assistant'}]