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
In post-ductal coarctation of aoa, collaterals may be formed by which of the following? 
Select and explain. 
A. Veebral aery, B. Suprascapular aery, C. Subscapular aery, D. None
D: None
Answer: D: None 
Explanation: Suprascapular aery, Subscapular aery, Posterior intercostal aery and Veebral Aery may all form channels for collateral ciculation in coarctation of aoa. The veebral aery is probably the least prominent pathway for collateral circulation amongst the options provided and hence may be accepted as the single best answer by exclusion.