Final answer:
The round ligaments of the uterus extend from its lateral margins, through the inguinal canal, to the external genitalia.
Step-by-step explanation:
The correct answer is that the round ligaments extend from the lateral margins of the uterus, through the inguinal canal to the external genitalia. This means that the round ligaments play a role in supporting the uterus by anchoring it to structures that are external to the abdominal cavity. The other ligaments associated with the uterus include the broad ligament, which supports the uterus by attaching laterally to both sides of the uterus and pelvic wall, and the uterosacral ligament, which helps in stabilizing the uterus posteriorly by connecting the cervix to the pelvic wall.