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
Which of the following is used in the treatment of differentiated thyroid cancer? 
Select and explain. 
A. 131I, B. 99mTc, C. 32p, D. 311–mIBG
A: 131I
Answer: A: 131I 
Explanation: The differentiated thyroid cancer and even the metastatic burden can be effectively controlled by I131 therapy.