This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Arrhythmias, Subject name: Medicine
Sinus Bradycardia is defined as heart rate of? 
Select and explain. 
A. Less than 40/min, B. Less than 50/min, C. Less than 60/min, D. Less than 70/min
C: Less than 60/min
Answer: C: Less than 60/min 
Explanation: Ans. is 'c' i.e., Less than 60/min