What Is the Correct Order in Which Action Potentials Spread $\rightarrow$

What is the correct order in which action potentials spread during a normal heartbeat in the mammalian heart?

A) Sinoatrial node $\rightarrow$ atrioventricular node $\rightarrow$ atrium $\rightarrow$ ventricle
B) Atrioventricular node $\rightarrow$ atrium $\rightarrow$ ventricle $\rightarrow$ sinoatrial node
C) Conducting system $\rightarrow$ atrioventricular node $\rightarrow$ ventricle $\rightarrow$ atrium
D) Sinoatrial node $\rightarrow$ conducting system $\rightarrow$ atrioventricular node
E) Sinoatrial node $\rightarrow$ atrium $\rightarrow$ atrioventricular node $\rightarrow$ conducting system $\rightarrow$ ventricle