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': 'The following is a marker of acute hepatitis B infection - \nSelect and explain. \nA. DNA polymerase, B. Hepatitis core antigen, C. Anti HBs, D. IgG to core antigen', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]