During the Cardiac Cycle,what Makes the Mitral and Tricuspid Valves

Multiple Choice

During the cardiac cycle,what makes the mitral and tricuspid valves close after the ventricles are filled with blood?

A) The chordae tendineae relax,which allows the valves to close.
B) The increased pressure in the ventricles pushes the values to close.
C) The trabeculae carneae contract,which pulls the valves closed.
D) The reduced pressure in the atria creates a negative pressure that pulls the valves closed.