This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Anatomy
Biopsy of the lower oesophagus in a patient with chronic reflux demonstrates epithelial metaplasia. Which of the following cell types was most likely observed in the involved areas? 
Select and explain. 
A. Ciliated columnar epithelium, B. Ciliated columnar epithelium, C. Keratinizing squamous epithelium, D. Nonciliated columnar epithelium
D: Nonciliated columnar epithelium
Answer: D: Nonciliated columnar epithelium 
Explanation: The medical condition is Barrett's esophagus, in which the normally nonkeratinizing squamous epithelium of the esophagus undergoes metaplasia to gastric or intestinal-like epithelium composed of nonciliated columnar epithelial cells.