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: Medicine
Ejection fraction denotes performance of - 
Select and explain. 
A. Left ventricle, B. Left atrium, C. Aortic valve, D. Pulmonary valve
A: Left ventricle
Answer: A: Left ventricle 
Explanation: None