Question

which bones unite to form the pubic synthesis?

Explanation:

The pubic symphysis is formed by the union of the pubic bones. In the pelvic structure, each hip bone (os coxae) has a pubic portion. The two pubic bones (one from each hip bone) come together at the midline to form the pubic symphysis.

Answer:

The pubic bones (from each hip bone) unite to form the pubic symphysis.