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: Ans. is 'c' i.e. Instrumentation", 'role': 'assistant'}]