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 Iodine 131 is – 
Select and explain. 
A. 8 hours, B. 8 days, C. 8 weeks, D. 8 months
B: 8 days
Answer: B: 8 days 
Explanation: None