Which bone is one of the three bones that make up the pelvic ring and consists of five fused vertebrae?

The sacrum is a critical component of the pelvic ring, consisting of five fused vertebrae. This unique structure provides stability and strength to the pelvis, allowing it to support the weight of the upper body when standing and during movement. As the sacrum connects the spine to the pelvis, it plays a vital role in maintaining proper alignment and transferring forces between the upper and lower parts of the body.

The other options do not relate directly to the characteristics described in the question. The pelvis is a general term referring to the entire structure composed of several bones, including the sacrum, but it isn’t specifically one of the three distinct bones that make up the pelvic ring. The scapula is a bone from the shoulder girdle, and the femur is the thigh bone, neither of which has any connection to the pelvic ring's structure composed of the iliac bones along with the sacrum. Thus, the sacrum stands out as the correct answer due to its specific anatomical role in the formation of the pelvic ring.