This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
The pacemaker of hea is: 
Select and explain. 
A. SA node, B. AV node, C. Both, D. None
A: SA node
Answer: A: SA node 
Explanation: The primary pacemaker of hea is SA node. It shows restless membrane potential similar to Interstitial cells of cajal,Pre-botzinger complex Ref:Guyton and Hall textbook of medical physiology 12th edition,page number:177