This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T., Subject name: Pathology
Characteristic of Barrett's esophagus is? 
Select and explain. 
A. Increased risk of SCC, B. Columnar Metaplasia, C. Most commonly in middle one third of esophagus, D. Gastric metaplasia is most common
B: Columnar Metaplasia
Answer: B: Columnar Metaplasia 
Explanation: Ans. is 'b' i.e. Columnar metaplasia * Barrett's esophagus is a metaplasia in which normal squamous epithelium of lower part of esophagus is replaced by columnar epithelium due to prolonged esophageal reflux.* Most common type of metaplasia in Barrett's esophagus is intestinal metaplasia which is characterized by presence of intestinal goblet cells in the metaplastic columnar epithelium.* Barrett's esophagus is a pre-malignant condition. It is the single most important risk factor for adenocarcinoma of esophagus.