Which term describes a flat bone that aids in shoulder formation?

The scapula, commonly referred to as the shoulder blade, is classified as a flat bone due to its thin and broad shape. This bone plays a crucial role in the structure and function of the shoulder. It serves as an attachment point for various muscles that facilitate movement and stability of the shoulder joint, including those that enable arm elevation and rotation. Additionally, the scapula works in conjunction with the humerus (upper arm bone) and clavicle (collarbone) to allow a wide range of motion in the arm, making it essential for numerous physical activities.

In contrast, the other options refer to different bones found in the body. The sacrum is a triangular bone located at the base of the spine and is an integral part of the pelvis. The pelvis, which consists of several bones including the ilium, ischium, and pubis, primarily supports the trunk and connects the vertebral column to the lower limbs. The coccyx, or tailbone, is a small, triangular bone located at the very end of the vertebral column and serves as an attachment site for ligaments and muscles, but it does not participate in shoulder formation.