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': 'A 32 weeks premature infants, 900gm weight on the third days. The serum bilirubin is 13 mg%. The treatment of choice is – \nSelect and explain. \nA. Exchange transfusion, B. Phototherapy, C. Wait and watch therapy, D. Pharmacologic therapy', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]