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: Physiology
[{'content': 'The following statements are true regarding the SA node except: \nSelect and explain. \nA. Is located at the right border of the ascending aoa, B. It contains specialized nodal cardiac muscle, C. It is supplied by the aial branches of the right coronary aery, D. It initiates cardiac conduction', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Is located at the right border of ascending aoa S.A node is located at the junction of superior venacave with right atriumQ just deep to the epicardium, near the superior end of sulcus terminalis and AV node is located in the right postero-inferior region of interatrial septum near the opening of coronary sinus.', 'role': 'assistant'}]