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: Anatomy
What is the uppermost structure in left lung hilum? 
Select and explain. 
A. Pulmonary aery, B. Pulmonary vein, C. Bronchial aery, D. Left mainstem bronchus
A: Pulmonary aery
Answer: A: Pulmonary aery 
Explanation: A i.e., Pulmonary aery