Which Statement Best Describes Why Clinicians Use a Defibrillator

Which statement best describes why clinicians use a defibrillator?

A) A defibrillator takes the place of the SA node and must be applied every minute to keep the heart rate normal until it regains its strength and beats on its own.
B) The applied current opens up voltage gated calcium channels in the atria causing the heart to begin a new P wave.
C) The applied current depolarizes all the muscle cells at the same time, returning synchronous electrical activity to the heart.
D) The applied current repolarizes the cells of the heart, hence resetting the heart for normal rhythm.
E) The ventricles of the heart are so large that only a strong current can make them depolarize, which is needed in order for them to contract and get blood to the body.