This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Upper limb, Subject name: Anatomy
A 52 year old woman presented with weakness of shoulder movements. Investigations revealed quadrangular space syndrome. Which of the following nerve is likely to be affected ? 
Select and explain. 
A. Brachial plexus, B. Axillary nerve, C. Median nerve, D. Radial nerve
B: Axillary nerve
Answer: B: Axillary nerve 
Explanation: Quadrangular space is a passageway for the nerves and vessels between the axilla anteriorly and scapular region posteriorly. It&;s contents are Axillary nerve Posterior circumflex humeral aery and vein Quadrangular space syndrome is a condition caused by hyperophy or fibrosis of quadrangular space muscles which impinge on axillary nerve. Patient present with weakness of shoulder movements. Ref : Gray&;s Anatomy The Anatomical Basics of Clinical Practice 41 e pg 814.