What wave represents ventricular repolarization in an ECG?

The T wave represents ventricular repolarization on an electrocardiogram (ECG). After the ventricles contract (this is indicated by the QRS complex), there is a recovery phase where the ventricular muscle cells return to their resting state, which is what the T wave signifies. The T wave reflects the electrical activity associated with this repolarization, essentially showing that the ventricles are preparing for the next heartbeat.

The P wave corresponds to atrial depolarization, showing when the atria contract as the heart rhythm begins. The QRS complex represents ventricular depolarization, which occurs just before the ventricles contract. The R wave is a part of the QRS complex, specifically highlighting the peak of ventricular depolarization, but it does not relate to repolarization at all. Therefore, the T wave is the only waveform in this context that signifies the recovery of the ventricular electrical state, making it the correct answer.