Answer:
preload
Step-by-step explanation:
Preload is the initial stretch of the ventricular muscle before contraction. It is determined by the amount of blood in the ventricle at the end of diastole. The higher the preload, the greater the tension in the ventricular wall, and the more forcefully the ventricle will contract.
The other options are not correct:
Frank-Starling law of the heart: The Frank-Starling law of the heart states that the force of contraction of the heart muscle is directly proportional to the preload.
Afterload: Afterload is the resistance against which the ventricle must pump blood during contraction.
Contractility: Contractility is the inherent ability of the heart muscle to contract.