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: Medicine
[{'content': 'Commonest cause of pyogenic liver abscess: \nSelect and explain. \nA. Appendicitis, B. Biliary sepsis, C. Infective endocarditis, D. Renal abscess', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Biliary tract disease is the commonest cause of bacterial liver abscess They are: Choledocholithiasis, obstructing tumours, strictures, congenital anomalies of the biliary tree Other causes are: Diveiculitis inflammatory bowel disease Perforated hollow viscera appendicitis. endocarditis or pyelonephritis. Ref: Heneghan et al. BMC Research Notes 2011, 4:80.', 'role': 'assistant'}]