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': 'Ejection fraction is \nSelect and explain. \nA. SV/EDV, B. EDV/SV, C. ESV/EDV, D. SV/EDV', 'role': 'user'}, {'content': 'Answer: A \nExplanation: It is the volumetric fraction of fliud ejected from the chamber on each contraction. Normal is greater than 60%', 'role': 'assistant'}]