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
[{'content': 'From the left ventricular pressure volume loop calculate Ejection fraction \nSelect and explain. \nA. 54%, B. 58%, C. 60%, D. 65%', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ejection fraction = Stroke volume / End diastolic volume = (130-60) /13 =0.538 =53.8%', 'role': 'assistant'}]