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: Radiology
In PA view of X-ray chest, right border of the hea is formed by all except: 
Select and explain. 
A. Superior venacava, B. Inferior venacava, C. Right atrium, D. Left atrial appendage
D: Left atrial appendage
Answer: D: Left atrial appendage 
Explanation: Ans. Left atrial appendage