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: Pediatrics
[{'content': 'The commonest route of transmission of HIV from the mother to the baby is – \nSelect and explain. \nA. Vertical transmission during pregancy, B. During delivery through vagina, C. Breast milk, D. Constant touch and handling', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]