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: Surgery
Poirier's triangle is bound by all except: 
Select and explain. 
A. Left bronchus, B. Arch of aorta, C. Left subclavian artery, D. Vertebral column
A: Left bronchus
Answer: A: Left bronchus 
Explanation: Thoracic duct is identified within Poirier's triangle which is formed by arch of aorta, left subclavian artery & vertebral column.