This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thorax, Subject name: Anatomy
SA Node is located at 
Select and explain. 
A. Upper end crista terminalis, B. Lower end of crista terminalis, C. At opening of IVC, D. At ostium primum
A: Upper end crista terminalis
Answer: A: Upper end crista terminalis 
Explanation: SA node is situated at the atriocaval junction in the upper pa of the sulcus terminalis B D CHAURASIA'S HUMAN ANATOMY UPPER LIMB THORAX-VOLUME 1 SIXTH EDITION Page no-262