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: Surgery
[{'content': 'What is safe maximum time for storage of kidney? \nSelect and explain. \nA. 24 hours, B. 48 hours, C. 36 hours, D. 80 hours', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Optimal time for kidney transplant is within 18 hours. Max peroid is 36 hours.', 'role': 'assistant'}]