Which statement correctly identifies the QRS Wave in relation to heart electrical activity?

• A. P Wave
• B. T Wave
• C. QRS Wave
• D. PR interval

Answer: (C)

The QRS complex represents ventricular depolarization—the rapid electrical activation that makes the ventricles contract. It comes after atrial depolarization, which is shown by the P wave, and ends as the ventricles complete their activation just before contraction finishes, which leads into the ventricles’ mechanical squeeze. The T wave, by contrast, shows ventricular repolarization, the ventricles resetting after contraction. The PR interval is a time measurement from the start of the P wave to the start of the QRS, reflecting conduction from the atria through the AV node to the ventricles, not the QRS itself. So identifying the QRS wave means recognizing it as the electrical event that triggers the ventricles to contract.