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': 'Amount of coronary flow per minute is: \nSelect and explain. \nA. 225 mL, B. 250 mL, C. 50 mL, D. 300 mL', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Coronary\xa0flow\xa0at\xa0rest\xa0in\xa0humans\xa0is\xa0about 250 mL/min (5% of the cardiac output).', 'role': 'assistant'}]