This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Skin, Bones and Joints, Subject name: Pathology
[{'content': "Arrange the following tumours according to increasing age group A. Ewing's Sarcoma B. Osteosarcoma C. Osteoclastoma D. Chondrosarcoma \nSelect and explain. \nA. B,D,A,C, B. C,B,D,A, C. D,A,C,B, D. A,B,C,D", 'role': 'user'}, {'content': "Answer: D \nExplanation: Tumours according to increasing age group A. Ewing's Sarcoma B. Osteosarcoma C. Osteoclastoma D. Chondrosarcoma", 'role': 'assistant'}]