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 malignant tumour in childhood \nSelect and explain. \nA. Rhabdomyosarcoma, B. Leukemia, C. Lymphangioma, D. Neuroblastoma', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Leukemia is the most common malignancy of childhood.There are two main subtypes,the commoner acute lymohoblastic leukemia(ALL) & acute myeloid leukemia(AML).A small propoion may have chronic myeloid leukemia(CML) and juvenile myelomonocytic leukemia(JMML).ALL is the most common childhood malignancy accounting for one-fouh of all childhood cancers. Reference:Essential pediatrics-Ghai,8th edition,page no:599.', 'role': 'assistant'}]