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?

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