This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Upper limb- bones and muscles(proximal) and scapular movement, Subject name: Anatomy
An 11-year-old boy falls down the stairs. A physician examines a radiograph of the boy's shoulder region (below). If the structure indicated by the letter A is calcified, which of the following muscles is most likely paralyzed? 
Select and explain. 
A. Deltoid, B. Teres major, C. Teres minor, D. Infraspinatus
D: Infraspinatus
Answer: D: Infraspinatus 
Explanation: Scapular notch transmits the suprascapular nerve below superior transverse ligament, whereas suprascapular aery and vein run over the ligament. The suprascapular nerve supplies supraspinatus and infraspinatus muscles. The axillary nerve innervates deltoid and teres minor muscles. Subscapular nerves innervate the teres major and subscapularis muscles