Final answer:
An increase in venous return is most likely to cause a larger end diastolic volume (EDV).
Step-by-step explanation:
An increase in venous return is most likely to cause a larger end diastolic volume (EDV). Venous return refers to the amount of blood flowing back to the heart from the veins. When there is an increase in venous return, more blood fills the ventricles during diastole, resulting in a larger EDV.