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
Most common cancer in children less than 10 years: 
Select and explain. 
A. Leukemia, B. Neuroblastoma, C. Brain tumor, D. Wilm's tumor
A: Leukemia
Answer: A: Leukemia 
Explanation: a. Leukemia(Ref: Nelson's 20/e p 2437, Ghai 8/e 599-607)Most frequent childhood cancers are: (in order of decreasing frequency) Leukemia (Most common is ALL)Q > Neuroblastoma > Wilms' tumor > Hepatoblastoma > Retinoblastoma