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: Anatomy
Cell lining of common bile duct is ? 
Select and explain. 
A. Stritified Columnar, B. Stratified squamous, C. Simple cuboidal, D. Simple columnar
D: Simple columnar
Answer: D: Simple columnar 
Explanation: Ans. is 'd' i.e., Simple columnar Gall bladder and common bile ducts are lined by simple columnar epithelium.