When a Rhythm Is Regular,with Narrow QRS Complexes,but Firing at a Rate

Multiple Choice

When a rhythm is regular,with narrow QRS complexes,but firing at a rate so fast that you can't distinguish the P waves to identify it more accurately,you can call the rhythm:

A) supraventricular tachycardia.
B) rapid ventricular response.
C) unidentifiable tachyarrhythmia.
D) tachycardia of unknown origin.