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: Anatomy
SA node is located in ? 
Select and explain. 
A. Triangle of Koch's, B. In crista terminalis, C. In membranous pa of interventricular septum, D. Upper pa of interatrial septum
B: In crista terminalis
Answer: B: In crista terminalis 
Explanation: In crista terminalis