**Core Concept**
The broad ligament of the uterus is a fold of peritoneum that extends from the sides of the uterus to the walls and floor of the pelvis. It plays a crucial role in supporting the uterus and surrounding structures. Understanding the contents of the broad ligament is essential for identifying potential sources of pelvic pain and other gynecological disorders.

**Why the Correct Answer is Right**
The correct answer is related to the contents of the broad ligament, which include the uterine vessels, the round ligament, the uterosacral ligament, the ovarian ligament, and the ligament of the ovary (also known as the infundibulopelvic ligament). These structures are embedded within the broad ligament and play a vital role in maintaining uterine function and supporting the ovary.

**Why Each Wrong Option is Incorrect**
* **Option A:** Incorrect because the round ligament is actually a structure that runs within the broad ligament, not a structure that is outside of it.
* **Option B:** Incorrect because the uterine vessels are indeed a part of the contents of the broad ligament.
* **Option C:** Incorrect because the ovarian ligament is a structure that connects the ovary to the uterus and is embedded within the broad ligament.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the broad ligament is a fold of peritoneum that contains several important structures, including the uterine vessels and the round ligament. Identifying these structures is crucial for diagnosing and managing various gynecological conditions.

**Correct Answer:** A. Round ligament.