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: Iodine 131 is a radioisotope with a very short half-life of 8.02 days, making it highly radioactive. Frequently used in small doses in thyroid cancers therapies, it is also one of the most feared fission products when accidentally released into the environment