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: Physiology
[{'content': 'Kidney receives how much percent of cardiac output: \nSelect and explain. \nA. 15%, B. 25%, C. 35%, D. 45%.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]