The correct answer 2. Congestive heart failure (CHF) is a condition where the heart is unable to pump blood efficiently enough to meet the body's needs. As a result, fluid may accumulate in various parts of the body. Cardiac preload refers to the volume of blood that fills the ventricles of the heart during diastole, the phase of the cardiac cycle when the heart is relaxed and filling with blood. There are two main types of congestive heart failure:

1. Systolic: the heart muscle becomes weakened and is unable to contract with enough force during each heartbeat to pump a sufficient amount of blood to meet the body's needs. This results in reduced ejection fraction (the percentage of blood ejected from the heart during each contraction). 

2. Diastolic: the heart muscle becomes stiff and is unable to relax properly during the relaxation phase of the cardiac cycle (diastole). This impairs the heart's ability to fill adequately with blood between beats, leading to decreased cardiac output.