This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
Most common bile duct tumor is 
Select and explain. 
A. Adenocarcinoma, B. Squamous cell carcinoma, C. Transitional cell carcinoma, D. All
A: Adenocarcinoma
Answer: A: Adenocarcinoma 
Explanation: Refer Robbins page no 874