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': 'Maximum dose of radiation which is considered safe for human in a year is: March 2010 \nSelect and explain. \nA. 5 Rads, B. 10 Rads, C. 15 Rads, D. 20 Rads', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A: 5 Rads', 'role': 'assistant'}]