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: Medicine
[{'content': "Barret's esophagus is commonly associated with one of the following: \nSelect and explain. \nA. Adenocarcinoma, B. Squamous cell carcinoma, C. Sarcoma, D. Gastrointestinal stromal tumor", 'role': 'user'}, {'content': "Answer: A \nExplanation: Answer is A (Adenocarcinoma) Barret's esophagus is a premalignant lesion and predisposes to adenocarcinoma of the lower (distal) esophagus.", 'role': 'assistant'}]