An 11-year-old boy falls down the stairs. A physician examines a radiograph of the boy's shoulder region. If the structure indicated by the letter A is calcified, which of the following muscles is most likely paralyzed?

(d) The scapular notch transmits the suprascapular nerve below the superior transverse ligament, whereas the suprascapular artery and vein run over the ligament. The suprascapular nerve supplies the supraspinatus and infraspinatus muscles. The axillary nerve innervates the deltoid and teres minor muscles. The subscapular nerves innervate the teres major and subscapularis muscles.