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
Radioresistant tumor is 
Select and explain. 
A. Ewing's sarcoma, B. Osteosarcoma, C. Retinoblastoma, D. Neuroblastoma
B: Osteosarcoma
Answer: B: Osteosarcoma 
Explanation: List of highly radioresistant tumors : Osteosarcoma Melanoma Pancreatic cancer Hepatocellular carcinoma