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 cause of esophageal performation is- \nSelect and explain. \nA. Acid ingestion, B. Hyperemesis, C. Instrumentation, D. Carcinoma infiltrating', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]