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
Half life of T4 is 
Select and explain. 
A. 20 minutes, B. 12 hours, C. 1 day, D. 6 days
D: 6 days
Answer: D: 6 days 
Explanation: 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.