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': 'Chronic active hepatitis is distinguished from chronic persistent hepatitis by - \nSelect and explain. \nA. Characteristic liver pathology, B. HBS Ag in serum, C. Extrahepatic manifestations, D. Presence of anti smooth muscle antibody', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]