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': 'A person who is HBsAg negative, Anti-HBs positive and Anti HBc positive, is most probably suffering from? \nSelect and explain. \nA. Immunity due to vaccination of hepatitis B, B. Immunity due to infection of hepatitis B, C. Acute infection of hepatitis B, D. Chronic infection of hepatitis B', 'role': 'user'}, {'content': 'Answer: B \nExplanation: HBsAg negative, Anti-HBs positive, Anti HBc positive means there is no surface antigen, which is the indicator of ongoing infection; but there is antibody against both the core and surface antigens. This shows that this person had an exposure to hepatitis B infection in the past and gained acquired immunity. Ref: The Encyclopedia of Hepatitis and Other Liver Diseases By James H. Chow, Cheryl Chow, 2006, Page 119.', 'role': 'assistant'}]