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': 'The small nonparticulate protein leading to enhanced replication of HBV as well as HIV is \nSelect and explain. \nA. HBc Ag, B. HBs Ag, C. Hbe Ag, D. HBx Ag', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]