This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
All of the following are features of Mobiz type I block except - 
Select and explain. 
A. Constant PR interval, B. Normal QRS morphology, C. Regular atrial rhythm, D. Atrial rate - ventricular rate
A: Constant PR interval
Answer: A: Constant PR interval 
Explanation: None