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': "Barrett's esophagus is commonly associated with one of the following: \nSelect and explain. \nA. Adenocarcinoma, B. Squamous cell carcinoma, C. Sarcoma, D. Gastrointenstinal stromal tumor", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]