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
Left border of hea on chest X-ray is formed by: 
Select and explain. 
A. Aoic arch, B. Left Pulmonary aery, C. Left ventricle, D. All
D: All
Answer: D: All 
Explanation: A i.e. Aoic arch; C i.e. Left ventricle; B i.e. Left Pulmonary aery