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': 'Which is the commonest childhood tumor - \nSelect and explain. \nA. ALL, B. CLL, C. AML, D. CML', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., ALL", 'role': 'assistant'}]