Final answer:
The ilium is the largest and uppermost part of the hip bone, articulating with the sacrum at the sacroiliac joint. The ischium and pubis are other parts of the hip bone, supporting the body and comprising the pelvic structure.
Step-by-step explanation:
The ilium is the uppermost and largest part of the hip bone, and it is indeed the component that forms the superior part of the hip bone. It articulates with the sacrum posteriorly at the sacroiliac joint, which is supported by the anterior and posterior sacroiliac ligaments.
The ischium forms the posteroinferior region of the hip bone and helps support the body when sitting, while the pubis is the anterior portion that joins with another pubis at the pubic symphysis. The cup-shaped cavity located on the lateral side of each hip bone, which is part of the hip joint is referred to as the acetabulum. The ilium, ischium, and pubis converge in this acetabulum.