This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology, Subject name: Microbiology
[{'content': 'In a patient only HBs Ag is positive ins serum, all other markers are negative, This indicates - \nSelect and explain. \nA. Acute hepatitis, B. Chronic active hepatitis, C. Persistent carrier, D. Hepatitis B vaccination', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Presence of only HBsAg indicate immunisation. REF:MICROBIOLOGY ANANTHA NARAYANAN NINTH EDITION PAGE.546&548', 'role': 'assistant'}]