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
Barrett's esophagus is commonly associated with one of the following: 
Select and explain. 
A. Adenocarcinoma, B. Squamous cell carcinoma, C. Sarcoma, D. Gastrointenstinal stromal tumor
A: Adenocarcinoma
Answer: A: Adenocarcinoma 
Explanation: None