The Most Important Factor in Ensuring That Blood Moves in Correct

The most important factor in ensuring that blood moves in correct order through the heart is (the)

A) location of the main electrical conduction node.
B) coordination of the timing of atrial and ventricular systole.
C) strength of the contraction of the different parts of the myocardium.
D) pressure of blood in each of the chambers at any given time.
E) None of the answers are correct.