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': 'Post irradiation thyroid tumor is: \nSelect and explain. \nA. Follicular CA, B. Papillary CA, C. Lymphoma, D. Huhle cell tumor', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Papillary CA Radiation is an etiological agent for papillary carcinoma thyroid & external radiation is used in treatment of anaplastic cancer thyroid.Q', 'role': 'assistant'}]