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: Physiology
[{'content': 'Half life of T4 is \nSelect and explain. \nA. 20 minutes, B. 12 hours, C. 1 day, D. 6 days', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans: D. 6 days(Ref: Ganong 25th/e p. 338-341; Understandings of medical physiology p. 7l9)Half life of T3 = 1 dayHalf life of T4 = 6 days.', 'role': 'assistant'}]