Reentry Occurs When

Reentry occurs when:

A) the atrial cells spontaneously depolarize and initiate impulses before the SA node has a chance to generate a normal impulse.
B) an electrical impulse goes back into a conduction pathway rather than moving from one end of the heart to the other and then terminating.
C) problems occur at the level of the ion channels in individual heart cells leading to partial repolarization which causes repetitive ectopic firing.
D) b and c