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: Pathology
[{'content': 'Which of the following is also known as australia antigen: September 2006 \nSelect and explain. \nA. HBsAg, B. HBeAg, C. HBcAg, D. HBV DNA', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A: HBsAg HBV was first linked to hepatitis in the 1960s when Australia antigen (later known as HBV surface-antigen) was identified.', 'role': 'assistant'}]