This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Skeletal system, Subject name: Radiology
Codman's triangle is a feature of - 
Select and explain. 
A. Osteosarcoma, B. Osteochondroma, C. Osteoid osteoma, D. Chondrosarcoma
A: Osteosarcoma
Answer: A: Osteosarcoma 
Explanation: A Codman triangle develops when a poion of periosteum is lifted off of the coex by tumor, pus, or hemorrhage at a leading edge . This aggressive form of periosteal reaction is commonly seen in osteosarcomas and occasionally with infection and metastases.