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': 'A patient complaining of difficulty of swallowing of solid\nfoods is suffering from all of the following except: \nSelect and explain. \nA. diffuse esophagus spasm, B. Achalasia cardia, C. esophageal carcinoma, D. bulbar palsy', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]