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': 'Acute Hepatitis B can be earliest diagnosed by? \nSelect and explain. \nA. IgM anti HBc ab, B. Hbs Ag, C. IgC anti HBc abs, D. Anti HBs Ag ab', 'role': 'user'}, {'content': "Answer: A \nExplanation: For the diagnosis of HBV infection detection of HBsAg in the blood is all that ordinarily necessary. The simultaneous presence of IgM anti-HBc indicates recent infection.occassionally when the level of HBsAg is too low to be detectable, the diagnosis has to be made by testing for IgM anti-HBc. REF:ANANTHANARAYAN AND PANIKER'S TEXTBOOK OF MICROBIOLOGY 9TH EDITION PAGE NO-547", 'role': 'assistant'}]