The contraction phase of the cardiac cycle refers to diastole.
a. true
b. false

The correct answer to the question: The contraction phase of the cardiac cycle refers to diastole, would be, B: false.

Explanation:

The cardiac cycle is defined as the process by which the heart fills up with both oxygenated and de-oxygenated blood, and pumps one towards the lungs for oxygenation and the other towards the body, to delived oxygen and other nutrients to the organs. In order to accomplish this function, the heart has two parts in its cycle, the sistole and diastole. The sistole is the part of the cycle when the heart literally squeezes its chambers, both the atria and mostly the ventricles, to pump out the blood present in them. Distole is the part of the cycle when the chambers relax, and open to their fullest extent, to permit the entrance of the necessary blood from the vessels, so that a new cycle can begin. This is why the answer would be false. Diastole is when the heart is relaxed and getting filled with blood.