This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Musculoskeletal Radiology, Subject name: Radiology
[{'content': '"Sunray appearance" on x-rays is suggestive of : \nSelect and explain. \nA. Chondrosarcoma, B. Metastatic tumor in the bone, C. Osteogenic sarcoma, D. Ewing\'s sarcoma', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Osteosarcoma - New bone is laid down along the blood vessels within the tumor growing centrifugally giving rise to a \'Sun -ray appearance\' on x -ray. Chondrosarcoma- "Speckled" calcification on x-ray Ewings sarcoma - Second most common malignant. Classic x-ray appearance is the "onion skin"', 'role': 'assistant'}]