This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Heart, Circulation, and Blood, Subject name: Physiology
Cardiac output in L/min divided by heart rate equals 
Select and explain. 
A. Cardiac efficiency, B. Mean stroke volume, C. Cardiac index, D. Mean arterial pressure
B: Mean stroke volume
Answer: B: Mean stroke volume 
Explanation: Ans. (b) Mean stroke volumeRef: Ganong, 25th ed/p.544Cardiac output is the product of heart rate (HR) and stroke volume (SV)So, Cardiac output/heart rate = stroke volume