Is located closest to the center of the heart A)left atrium B)AVnode C) SA node D) atrioventricular bundle.?

The structure located closest to the center of the heart is the B) AV node (atrioventricular node). It is situated in the interatrial septum near the center of the heart, receiving impulses from the SA node and relaying them to the ventricles. The left atrium, SA node, and atrioventricular bundle are positioned at varying distances from the center.