This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Medicine
Ejection fraction denotes performance of- 
Select and explain. 
A. Left ventricle, B. Left atrium, C. Aoic valve, D. Pulmonary valve
A: Left ventricle
Answer: A: Left ventricle 
Explanation: ejection fraction (EF) is the fraction of blood ejected from a ventricle of the hea with each hea beat .It is a direct indicater of left ventricular function EJECTION FRACTION * The volume of blood within a ventricle immediately before a contraction is known as the end-diastolic volume. * The volume of blood left in a ventricle at the end of contraction is end-systolic volume. * The difference between end-diastolic volume (EDV) and end-systolic volumes (ESV) is the stroke volume, the volume of blood ejected with each beat. * Ejection fraction (Ef) is the fraction of the end-diastolic volume that is ejected with each beat; that is, it is stroke volume (SV) divided by end-diastolic volume (EDV) Ref : Harrison 20th edition pg 1437