Final answer:
Scapular adduction (retraction) primarily involves the trapezius, rhomboids, and levator scapulae; these muscles pull the scapulae towards the spine. The pectoralis minor and serratus anterior are not primary contributors to this movement, as they serve in scapular protraction and rotation.
Step-by-step explanation:
The muscles involved in scapular adduction, also known as retraction, include the trapezius, rhomboids (which include rhomboid major and rhomboid minor), and levator scapulae. These muscles work together to move the scapulae medially, pulling them towards the vertebral column. This action is opposed to scapular abduction (protraction), in which the scapulae are moved away from the spine.
The pectoralis minor and serratus anterior primarily perform other actions; the pectoralis minor helps with downward rotation and depression of the scapula, and the serratus anterior facilitates scapular protraction and upward rotation. Therefore, these muscles are not primary contributors to scapular adduction.
The correct muscles involved in scapular adduction are not listed together in any of the options provided (A, B, C, D), suggesting a mismatch in the question choices. Typically, the correct combination for scapular retraction muscles would include the trapezius and rhomboids without the pectoralis minor and serratus anterior, which perform different actions.