This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Anatomy
[{'content': 'Most common cause of cholangitis \nSelect and explain. \nA. Viral infection, B. CBD stone, C. Surgery, D. Amoebic infection', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Cholangitis Ascending bacterial infection of the biliary ductal system with obstruction Most common cause of acute cholangitis is choledocholithiasis Most common organism present in the bile in patients with cholangitis : E.coli, Klebsiella pneumoniae, streptococcus faecalis & Bacteroides fragilis Etiology Choledocholithiasis(MC) Benign strictures Biliary enteric anastomotic strictures Cholangiocarcinoma and periampullary cancer Ref: Sabiston 20th edition Pgno :1507', 'role': 'assistant'}]