Of the list below, select the one that gives the least explanation for the relatively high mobility of the arms.
◦ The relatively open glenoid cavity of the glenohumeral joint.
◦ The scapula does not articulate to the axial skeleton directly.
◦ The subscapular notch is a passage way for nerves.
◦ The clavicle articulates to the axial skeleton at only the sternal end.