Which statement is true?

The true statement is: **Bones provide shape to the body.**

Bones play a crucial role in giving structure and support to the body, helping to define its shape. The other statements are not accurate. Bones do not help the heart pump blood (that is the role of the heart itself and the circulatory system), bones are not composed of a single layer (they are complex structures made up of multiple layers of cells and minerals), and bones are not classified as an organ system; rather, they are individual organs that make up the skeletal system.