**Core Concept**
The supports of the uterus are a complex system of ligaments, muscles, and fasciae that maintain its position and prevent prolapse. The main supports include the uterosacral ligaments, Mackenrodt's ligament (cardinal ligament), and the levator ani muscles.

**Why the Correct Answer is Right**
The broad ligament is a fold of peritoneum that attaches the uterus to the pelvic sidewalls and floor, but it does not provide significant support to the uterus. In fact, the broad ligament is often considered a suspensory ligament, allowing for some degree of movement and flexibility of the uterus. In contrast, the uterosacral ligaments and Mackenrodt's ligament provide direct support to the uterus, preventing it from prolapsing into the vagina. The levator ani muscles also play a crucial role in supporting the pelvic organs, including the uterus.

**Why Each Wrong Option is Incorrect**
**Option A:** The uterosacral ligaments are indeed a key support of the uterus, providing direct attachment to the cervix and preventing prolapse.
**Option B:** Mackenrodt's ligament (cardinal ligament) is also a vital support of the uterus, providing lateral support and preventing prolapse.
**Option D:** The levator ani muscles are essential for supporting the pelvic organs, including the uterus, and are a critical component of the pelvic floor.

**Clinical Pearl / High-Yield Fact**
The supports of the uterus can be remembered using the mnemonic "UTERUS": Uterosacral ligaments, Uterine fascia, Tendinous insertions (Mackenrodt's ligament), Endopelvic fascia, Rectouterine pouch (broad ligament), and Sacral promontory.

**✓ Correct Answer: C. Broad ligament**