This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Oesophagus, Subject name: Medicine
Barrett's esophagus causes which cancer: 
Select and explain. 
A. Adenocarcinoma, B. Squamous cell CA, C. Carcinoid tumor, D. Esophageal leiomyoma
A: Adenocarcinoma
Answer: A: Adenocarcinoma 
Explanation: Ans. (a) AdenocarcinomaRef: Harrison's 17th ed. Ch. 286* Metaplastic columnar epithelium develops during healing of erosive esophagitis with continued acid reflux since columnar epithelium is more resistant to acid- pepsin damage than is squamous epithelium.* The metaplastic epithelium has different epithelial types, including goblet cells and columnar cells.* Finding intestinal metaplasia with goblet cells in the esophagus is diagnostic of Barrett's esophagus; this type of mucosa is thought to be at risk of cancer