It Is Important That the Atrioventricular (AV) Node Produce a Delay

It is important that the atrioventricular (AV) node produce a delay between the contraction of the atria and the contraction of the ventricles because this allows the

A) heart to rest for a brief period of time.
B) ventricles to fill to capacity.
C) ventricles to contract in smooth synchrony.
D) atria to contract in smooth synchrony.