This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bone Tumour, Subject name: Orthopaedics
[{'content': '22 year old male presents with bony mass in the metaphyseal region of right knee with typical sun ray appearance and CT Scan of the chest reveals osteoblastic metastases. What is the most probable diagnosis? \nSelect and explain. \nA. Osteosarcoma, B. Chondrosarcoma, C. Ewings sarcoma, D. Osteochondroma', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Osteosarcoma* 22 year old male with bony mass in the metaphyseal region of right knee with typical sun ray appearance and CT Scan of the chest with osteoblastic metastases is most likely to be suffering from osteosarcoma.", 'role': 'assistant'}]