This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Liver disorders, Subject name: Pediatrics
[{'content': "A 45 day old infant developed icterus and two days later symptoms and signs of acute liver failure appeared. Child was found to be positive for HbsAg. The mother was also HBsAg carrier. The mother's hepatitis B serological profile is likely to be: \nSelect and explain. \nA. HbsAg positive, B. HbsAg and HbeAg positivity, C. HbsAg and anti-Hbe antibody positivity, D. Mother infected with mutant HBV", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Most impoant risk factor that determines perinatal transmission of Hepatitis B is HBeAg HBsAg carrier mothers who are HBe Ag positive almost invariably (> 90%) transfer infection to their offspring.', 'role': 'assistant'}]