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': 'Most common cause of HIV infection in infant is ? \nSelect and explain. \nA. Perinatal transmission, B. Breast milk, C. Transplacental, D. Umbilical cord sepsis', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Perinatal transmission", 'role': 'assistant'}]