This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Radiotherapy, Subject name: Radiology
[{'content': 'Radioresistant tumor is - \nSelect and explain. \nA. Ewings sarcoma, B. Retinoblastoma, C. Osteosarcoma, D. Neuroblastoma', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Osteosarcoma o Most radio-resistant tumors areOsteosarcomaMelanomaHepatic carcinomaPancreatic carcinoma", 'role': 'assistant'}]