During Which Phase of the Cardiac Cycle Does the Mitral

During which phase of the cardiac cycle does the mitral valve open?

A) Atrial systole
B) Isovolumetric ventricular contraction
C) Rapid ventricular ejection
D) Reduced ventricular ejection
E) Isovolumetric ventricular relaxation
F) Rapid ventricular filling
G) Reduced ventricular filling (diastasis)