Based on this strip, which is the correct interpretation of this rhythm?

A. Accelerated junctional rhythm: An accelerated junctional rhythm originates in the AV junction (40-100 bpm), typically has absent, inverted, or hidden P waves (before, during, or after QRS), and a regular rhythm. This strip has clear, upright P waves, an irregular rhythm, and a lengthening PR interval. B. Premature atrial contractions (PAC): PACs are single ectopic beats that occur earlier than expected, originating in the atria. While they involve P waves, they don't show a pattern of progressively lengthening PR intervals or dropped beats in the characteristic Wenckebach pattern. C. Atrial fibrillation (A-fib): Atrial fibrillation is characterized by irregularly irregular R-R intervals, chaotic atrial activity with no discernible P waves, and a variable ventricular rate. This strip clearly shows discernible P waves. D. Wenckebach, Mobitz Type I atrioventricular (AV) block: This rhythm is defined by a progressive lengthening of the PR interval until a QRS complex is dropped. The cycle then repeats. This is what is observed in the ECG strip.