What is the primary function of the scapula?

The primary function of the scapula, or shoulder blade, is indeed to help form the shoulder. It plays a critical role in the shoulder girdle by providing attachment points for several muscles that enable a range of motions at the shoulder joint. The scapula connects to the humerus (the upper arm bone) at the glenohumeral joint, facilitating movements such as lifting, reaching, and rotating the arm.

While other functions like supporting the spine, protecting the rib cage, and connecting limbs to the trunk are important for overall anatomy and function of the body, they are not the primary roles of the scapula. The structure's design and its articulation with the humerus and other surrounding bones highlight its main role in providing stability and mobility for the shoulder joint, making option B the correct choice.