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': 'What percentage of cardiac output is supplied to kidneys? \nSelect and explain. \nA. 10%, B. 20%, C. 30%, D. None of the above', 'role': 'user'}, {'content': "Answer: B \nExplanation: The paired renal aeries take 20% of cardiac output to supply organs that represent less than one-hundredth of total body weight. Ref: Gray's anatomy 40th edition, Chapter 91.", 'role': 'assistant'}]