Final answer:
The arthrokinematic motion of the humeral head as the arm returns to the anatomical position after reaching upwards is characterized by an inferior roll and a superior glide of the humeral head, corresponding to answer C.
Step-by-step explanation:
The arthrokinematic motions refer to the subtle movements that take place at the joint surfaces during physiological joint motion. Specifically in the context of the humeral head at the glenohumeral joint after reaching upward into a cabinet, when the arm returns to the anatomical position, the correct arthrokinematic motion would be a combination of inferior rolling of the humeral head with superior gliding. This occurs because, during arm lowering or adduction from an elevated position, the convex humeral head moves opposite to the limb's movement, which is inferiorly, while the opposite surface of the joint capsule allows the humeral head to glide superiorly to maintain joint congruency. Thus, the accurate answer to the question is C. Rolls inferiorly, glides superiorly.