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: Radiology
[{'content': "Codman's triangle is a feature of – \nSelect and explain. \nA. Osteosarcoma, B. Osteochondroma, C. Osteoid osteoma, D. Chondrosarcoma", 'role': 'user'}, {'content': "Answer: A \nExplanation: Codman's triangle is characteristically seen in osteosarcoma.\xa0It may also be seen in\xa0Ewing's sarcoma and osteomyelitis.", 'role': 'assistant'}]