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: Surgery
Hallmark of Barrett's epithelium is 
Select and explain. 
A. Mucus secreting goblet cells, B. Transitional columnar epithelium, C. Stratified squamous epithelium, D. Acid producing parietal cells
A: Mucus secreting goblet cells
Answer: A: Mucus secreting goblet cells 
Explanation: Barrett's oesophagus is a metaplastic change in the lining mucosa of the oesophagus in response to chronic gastro-oesophageal refluxThis adaptive response involves a mosaic of cell types, probably beginning as a simple columnar epithelium which becomes 'specialised' with time. The hallmark of 'specialised' Barrett's epithelium is the presence of mucus-secreting goblet cells (intestinal metaplasia).Ref: Bailey and Love 27e pg: 1081