Cardiac cycle is stable or change over the years?

The cardiac cycle is defined as the steps involving the conversion of deoxygenated blood to oxygenated blood in the lungs and pumping it by the heart to the body through the aorta. So i think it would be stable over the years unless u have factors that will affect the cycle depending on a persons health

It’s either c or d as the answer.

Idon't bro i wish i could i'm so sorry