During ventricular diastole,

During joint diastole,..........

Which of the following statements regarding the cardiac cycle is incorrect?

During systole,what happens in the heart?

Stroke volume $= .......$

$A$: Isovolumetric systole of a normal cardiac cycle is responsible for the opening of semilunar valves causing the blood flow into aortic aorta and pulmonary aorta.
$R$: During isovolumetric systole,intraventricular pressure increases as semilunar and $AV$ valves are closed and ventricles are contracting.