Considering the left ventricle, why does isovolumetric ventricular contraction occur during ventricularsystole?

A) The ventricle needs to pressurize the blood to close the aortic valve.
B) Ventricular pressure is greater than atrial pressure so the ventricle cannot eject blood.
C) The bicuspid valve needs time to shut before the ventricle can eject blood.
D) Aortic pressure is higher than ventricular pressure and the ventricle must pressurize the blood to open the aortic valve.
E) The ventricle is still filling with blood and therefore cannot eject blood during this time.