This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Physiology
From the left ventricular pressure volume loop calculate Ejection fraction 
Select and explain. 
A. 54%, B. 58%, C. 60%, D. 65%
A: 54%
Answer: A: 54% 
Explanation: Ejection fraction = Stroke volume / End diastolic volume = (130-60) /13 =0.538 =53.8%