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: Surgery
[{'content': 'Which drug is used for Achalasia cardia- \nSelect and explain. \nA. Nifedipine, B. Propranolal, C. Atenolol, D. Bethnecol', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]