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 is the most common symptom of achalasia \nSelect and explain. \nA. Regurgitation, B. Dysphagia, C. Heartburn, D. Weight loss', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Dysphagia is the most common symptom seen in 95% of the patients.\nInitially it is more to liquids. In later stages both solids and liquids.\nRegurgitation is the second most common symptom and earliest symptom.', 'role': 'assistant'}]