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
Half-Life of I-131 is 
Select and explain. 
A. 8 days, B. 13 hours, C. 2-3 hours, D. 28 years
A: 8 days
Answer: A: 8 days 
Explanation: I-131 - 8 days
I-123 - 13 hours
I-132 -2-3 hours