This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: DNB 2018, Subject name: Medicine
[{'content': 'What is the t1/2 of T4? \nSelect and explain. \nA. 3-4 days, B. 5-6 days, C. 6-7 days, D. 7-8 days', 'role': 'user'}, {'content': 'Answer: C \nExplanation: T4 t 1/2 =5-7 days T3 t 1/2 = 1 day', 'role': 'assistant'}]