This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thorax, Subject name: Anatomy
VAN (vein, artery, nerve) sequence is present in intercostal space at: 
Select and explain. 
A. Upper border of rib, B. Middle border of rib, C. Lower border of rib, D. Middle portion of intercostal space
C: Lower border of rib
Answer: C: Lower border of rib 
Explanation: Ans. C Lower border of ribRef: Snell's Clinical Anatomy, pg. 41* There are 11 intercostal spaces within the thoracic wall. The spaces are tilled in by 3 layers of intercostal muscles and their related fasciae and are bounded superiorly and inferiorly by the adjacent ribs.* The costal groove is located along the inferior border of each rib (upper aspect of the intercostal space) and provides protection for the vein which is most superior and the nerve which is inferior in the groove (VAN).