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: Surgery
[{'content': 'Bone tumour arising from metaphysis: September 2012 \nSelect and explain. \nA. Osteogenic sarcoma, B. Ewing sarcoma, C. Osteoclastoma, D. Osteoid osteoma', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. A i.e. Osteogenic sarcoma Osteosarcoma Location: Metaphysis MC site in body: Lower end of femur X-ray appearance: - Sunburst appearance, - Codman's triangle Special feature: Secondaries in lungs Treatment: - Chemotherapy, - Limb salvage surgery", 'role': 'assistant'}]