Answer:
The answer is A. ventricular depolarization.
Step-by-step explanation:
In a normal electrocardiographic plot, the QRS complex is the graphic manifestation of depolarization of the ventricles. It usually has a weevil form in the ECG. This wave appears after the P wave (contraction of the atria) and because the ventricles have greater muscle mass, this QRS complex is larger. In addition to having a very specialized conduction system (His / Purkinje system), it coordinates the depolarization of the ventricles at a very high conduction velocity and, as a consequence, the waves of the QRS complex tend to be very narrow and peak-shaped, in instead of rounded.