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': 'In ca esophagus predisposing factors ? \nSelect and explain. \nA. Tylosis, B. Smoking, C. Lye stricture, D. All', 'role': 'user'}, {'content': "Answer: D \nExplanation: Answer is 'a' i.e. Tylosis; 'b' i.e. Smoking; 'c' i.e. Lye stricture", 'role': 'assistant'}]