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
[{'content': 'Fibromuscular wall is seen in - \nSelect and explain. \nA. Gall bladder, B. Duodenum, C. Jejunum, D. ileum', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The extrahepatic biliary tree and gallbladder share a similar microscopic anatomy, consisting of a fibromuscular wall lined by mucin producing columnar epithelium similar to that seen in intrahepatic bile ducts.', 'role': 'assistant'}]