This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S., Subject name: Pediatrics
[{'content': 'MC malignancy in children is: \nSelect and explain. \nA. Retinoblastoma, B. Leukemia, C. Wilms tumor, D. Neuroblastoma', 'role': 'user'}, {'content': 'Answer: B \nExplanation: b. Leukemia(Ref: Nelson 20/e p 2416)Most frequent childhood cancers are: (in order of decreasing frequency)Leukemia (Most common is ALL)Brain TumorsNeuroblastomaWilms tumor', 'role': 'assistant'}]