This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Radiation treatment planning, Subject name: Radiology
[{'content': "Which of these tumors is least radiosensitive \nSelect and explain. \nA. Ewing's sarcoma, B. Osteosarcoma, C. Wilm's tumor, D. Neuroblastoma", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. is \'b\' i.e. Osteosarcoma Repeated innumerable timesOsteosarcoma is least radiosensitive out of the four.Radiosensitivity of differenttumors A)Highly Sensitive C)Relatively resistant LymphomaSeminomaMyelomaEwing\'s Sq cell Ca of lung Hypernephroma Rectal Carcinoma Bladder carcinomaB)Wilms tumor Moderately sensitiveSmall cell Ca of lung Breast cancer Basal cell Ca D)Soft tissue sarcoma Carcinoma of the cervix Highly resistant Melanoma Osteosarcoma Pancreatic Medulloblastoma TeratomaOvarian cancer * About neuroblastoma, Devita\'s Oncology, 7/e, p 1907 writes - "Neuroblastoma is very sensitive to ionizing radiation".', 'role': 'assistant'}]