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
All of the following statements are false about stroke volume EXCEPT: 
Select and explain. 
A. Determined by after load, B. Determined by pre-diastolic volume, C. Decreases by increase in heart rate, D. Increased by increase in heart rate
C: Decreases by increase in heart rate
Answer: C: Decreases by increase in heart rate 
Explanation: Ans. C Decreases by increase in heart rateRef: Ganong, 25th ed. pg. 570-71* Basically it is asking here about the TRUE statement among the given choices.* Stroke volume is indirectly proportional to heart rate* Stroke volume = cardiac output/heart rate* As the heart rate increases, stroke volume decreases.* After load is determined by peripheral resistance. Therefore, it has nothing to do with stroke volume determination.* Stroke volume depends upon end diastolic volume (NOT pre-diastolic volume)