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: Medicine
[{'content': 'If a person has a hea rate of 70 beats/min, a left ventricular end diastolic volume of 100 ml, and an ejectionfraction of 0.50, then the cardiac output is \nSelect and explain. \nA. 3.0 liters/ min, B. 3.5 liters/ min, C. 4.0 liters/min, D. 4.5 liters/ min', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Cardiac output = hea rate x stroke volume. The ejection fraction = stroke volume/left ventricular end- diastolic volume (LVEDV). Therefore, stroke volume ejection fraction x L VEDV, or 0.50 x 100 ml = 50 nit Cardiac output = 50 ml x 70 beats/mm = 3500 mI/minute, or 3.5 liters/mm.', 'role': 'assistant'}]