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: Physiology
[{'content': 'Ejection fraction increases with: \nSelect and explain. \nA. End systolic volume., B. End diastolic volume., C. Peripheral vascular resistance., D. Venodilation.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ganong 22 -\nThe amount of blood ejected by each ventricle per stroke at rest is 70 to 90 ml. the end diastolic ventricular volume is about 130 ml. thus, about 50 ml of blood remains in each ventricle at the end of systole (end systolic ventricular volume), and the ejection fraction, the percent of the end diastolic ventricular volume that is ejected with each stroke, is about 65%. The ejection fraction is a valuable index of ventricular fraction.', 'role': 'assistant'}]