This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disease of Infancy & Childhood, Subject name: Pathology
[{'content': "Most common cause of extracranial solid tumor in children: \nSelect and explain. \nA. Neuroblastoma, B. Wilm'stumor, C. Thymoma, D. Osteosarcoma", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Neuroblastoma(Ref: Robbins 9th/pg 475-479)Neuroblastoma is the:Most common extracranial solid tumor of childhood QMost common abdominal tumor of childhood QMost frequendy diagnosed tumor of infancy (<1yr of age) Q', 'role': 'assistant'}]