Final answer:
The pubofemoral ligament is the one arching across the inferior aspect of the pubic symphysis, connecting the pubis to the femur.
Step-by-step explanation:
The ligament that arches across the inferior aspect of the pubic symphysis is the pubofemoral ligament. This intrinsic ligament spans the pubis of the hip bone to the femur, on the anterior-inferior aspect of the hip joint. The pubic arch itself is formed by the pubic symphysis, the bodies and inferior pubic rami of the adjacent pubic bones, which extends downward to join the ischial ramus, together forming the ischiopubic ramus. The subpubic angle is created by the medial convergence of the right and left ischiopubic rami.