This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Childhood tumors, Subject name: Pediatrics
[{'content': "Most common extracranial solid tumor in children is \nSelect and explain. \nA. Wilm's tumor, B. Neuroblastoma, C. Hydronephrosis, D. Rhabdomyosarcoma", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Neuroblastoma is the most common extracranial solid tumor in children and the most commonly diagnosed malignancy in infants. Reference: Nelson; Neuroblastoma; Page no: 2461', 'role': 'assistant'}]