"passive refilling of the heart occurs during which phase of the cardiac cycle? "

It occurs during the first phase via venous return where blood returns from depleted organs and fills the atrium until the pressure causes the AV valves to open and passively fill 80% of the ventricle.

that is true   : ) hope this you

i think it’s c but i might be wrong. if i am let me know! have a good rest of your day as well!