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': "Commonest complication of Zenker's diverticulum is \nSelect and explain. \nA. Dysphonia, B. Gastroesophageal reflux, C. Lung abscess, D. Perforation", 'role': 'user'}, {'content': 'Answer: C \nExplanation: "Pulmonary infection is the most frequent serious complication, and many patients are first seen after experiencing repeated episodes of pneumonia."-CSDT\n\nAspiration pneumonia & Lung abscess are the most frequent complications of Zenker\'s diverticulum.\nOther rare complications are:\nPerforation\nBleeding\nCarcinoma', 'role': 'assistant'}]