This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gallbladder, Subject name: Surgery
[{'content': "Mirizzi's syndrome is: \nSelect and explain. \nA. GB stone compressing common hepatic duct, B. GB carcinoma invading IVC, C. GB stone causing cholecystitis, D. Pancreatic carcinoma", 'role': 'user'}, {'content': "Answer: A \nExplanation: Mirizzi's Syndrome (Functional Hepatic Syndrome) Obstruction of the common hepatic duct or CBD by external compression or by erosion of stone in the Hamann pouch or cystic duct", 'role': 'assistant'}]