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': 'Which of the following is used in the treatment of differentiated thyroid cancer? \nSelect and explain. \nA. 131I, B. 99mTc, C. 32p, D. 311–mIBG', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The differentiated thyroid cancer and even the metastatic burden can be effectively controlled by I131\xa0therapy.', 'role': 'assistant'}]