An older patient who had previously recovered from a heart attack was experiencing slight chest discomfort, dizziness, palpitations and shortness of breath. He was taken to the emergency room via ambulance where an electrocardiogram (ECG) showed increased heart rate (> 100 beats / min) and a long QRS (> 0.12 s). He was diagnosed with wide complex tachycardia with a ventricular origin and properly treated. Which part of his ECG corresponds to atrial repolarization? select one:

a. The QRS duration.
b. None of the options .
c. The T wave.
d. The PR interval.
e. The P wave.