Final answer:
The round ligament is best described as a structure that attaches to the uterus, extending through the inguinal canal, and supports the uterus laterally within the pelvic cavity.
Step-by-step explanation:
The description that best matches the term round ligament is A) enters the inguinal canal. The round ligament attaches to the uterus near the uterine tubes and extends to the labia majora, passing through the inguinal canal. This ligament serves to maintain the position of the uterus within the abdominopelvic cavity and supports the uterus by attaching it laterally to the pelvic wall.