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
Posterior border of heart is formed by all except? 
Select and explain. 
A. Pulmonary artery, B. Left atrium, C. Left ventricle, D. Right  atrium
D: Right  atrium
Answer: D: Right  atrium 
Explanation: From above downwards(Posterior border) :
a. Pulmonary artery.
b. Left atrium.
c. Left ventricle.