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': 'Intermittent dysphagia is caused by \nSelect and explain. \nA. Stricture, B. Achalasia cardia, C. Pharyngeal diveiculum, D. All', 'role': 'user'}, {'content': "Answer: C \nExplanation: Answer is C (Pharyngeal diveiculum) Progressive Achalasia Progressive systemic sclerosis Peptic stricture Carcinoma Intermittent Lower esophageal ring/Spatzki ring Diffuse esophageal spasm Zenker's diveiculum", 'role': 'assistant'}]