This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2017, Subject name: Medicine
The PR interval in ECG denotes? 
Select and explain. 
A. Atrial depolarization only, B. Atrial depolarization with A - V conduction, C. Ventricular depolarization and ventricular repolarization, D. Atrial depolarization with atrial repolarization
B: Atrial depolarization with A - V conduction
Answer: B: Atrial depolarization with A - V conduction 
Explanation: Atrial depolarization only - P- Wave Ventricular depolarization and ventricular repolarization - QT interval