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
[{'content': 'Half-Life of I-131 is \nSelect and explain. \nA. 8 days, B. 13 hours, C. 2-3 hours, D. 28 years', 'role': 'user'}, {'content': 'Answer: A \nExplanation: I-131 - 8 days\nI-123 - 13 hours\nI-132 -2-3 hours', 'role': 'assistant'}]