Rotator cuff muscles.

• A. deltoid, biceps brachii, trapezius, latissimus dorsi
• B. supraspinatus, infraspinatus, teres minor, subscapularis
• C. supraspinatus, infraspinatus, teres major, subscapularis
• D. supraspinatus, infraspinatus, teres minor, deltoid

Answer: (B)

The rotator cuff forms a stabilizing cuff around the shoulder joint, keeping the head of the humerus centered in the glenoid cavity during movement. The four muscles that make up this group are supraspinatus, infraspinatus, teres minor, and subscapularis. Supraspinatus helps start the first part of arm lifting (abduction); infraspinatus and teres minor primarily externally rotate the arm; and subscapularis internally rotates the arm. Together they originate on the scapula and attach to the humerus, creating a tight, supportive ring that stabilizes the joint while the larger shoulder muscles move the arm.

The other options include muscles that are not part of the rotator cuff, such as deltoid, biceps brachii, trapezius, latissimus dorsi, and teres major, which have different roles and are not the cuff’s stabilizers. Therefore, the set that lists supraspinatus, infraspinatus, teres minor, and subscapularis best matches the rotator cuff.