Which of the following decreases the cardiac ?output Preload .a Afterload .b Venous return .C Contractility of the heart .d

The correct answer is **a. Preload**.<br /><br />Preload refers to the degree of stretch of the heart muscle before contraction. When preload decreases, it means that the heart stretched as much, which can lead the force of contraction and ultimately a decrease in cardiac output.