This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Intestinal Infections, Worm Infestations, Subject name: Social & Preventive Medicine
[{'content': 'Marker of Infectivity of Hepatitis B is:- \nSelect and explain. \nA. HBsAg, B. HBeAg, C. Anti HBs, D. Anti HBs', 'role': 'user'}, {'content': 'Answer: B \nExplanation: HBsAg first antigen to appear, epidemio marker ( Australian antigen ) HBcAg - Rarely appears in plasma HBeAg - Marker of infectivity 1st Ab to appearance - Anti HBC Ab - acute hepatitis IgM Anti HBe - Marker of good prognosis Anti HBs - End of communicability and vaccinated.', 'role': 'assistant'}]