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: Microbiology
[{'content': 'Infectivity of HBV is indicated by ? \nSelect and explain. \nA. HBeAg, B. HbsAg, C. HBV DNA, D. Anti HBs Ag', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., H BeAg", 'role': 'assistant'}]