Final answer:
The QRS complex of the EKG represents ventricular depolarization.
Step-by-step explanation:
The QRS complex of the EKG represents ventricular depolarization, which is option b. The QRS complex is a large waveform on the EKG that corresponds to the electrical activation and contraction of the ventricles. It is an important indicator of the heart's ability to pump blood effectively.
Ventricular depolarization refers to the phase of the cardiac cycle during which the ventricles of the heart undergo an electrical depolarization, leading to the contraction of the ventricular muscle and subsequent ejection of blood into the pulmonary artery and aorta. The electrical events that occur during ventricular depolarization are represented on an electrocardiogram (ECG or EKG).