**Core Concept**
The main support of the uterus is provided by a strong, fibrous structure that connects it to the pelvis. This structure plays a crucial role in maintaining the uterine position and preventing its prolapse.

**Why the Correct Answer is Right**
The main support of the uterus is provided by the cardinal ligaments, also known as Mackenrodt's ligaments. These ligaments are formed by the condensation of the endopelvic fascia and are composed of tough, fibrous tissue that attaches the uterus to the lateral walls of the pelvis. The cardinal ligaments work in conjunction with the uterosacral ligaments to provide the main support to the uterus.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not provided, but typically, the round ligaments are not considered the main support of the uterus. They do, however, provide some support and help maintain the uterine position.
* **Option B:** The broad ligament of the uterus does provide some support, but it is not considered the main support. It is a fold of peritoneum that attaches the uterus to the lateral walls of the pelvis.
* **Option C:** The uterosacral ligaments do provide some support to the uterus, but they are not considered the main support. They work in conjunction with the cardinal ligaments to maintain the uterine position.

**Clinical Pearl / High-Yield Fact**
The cardinal ligaments are a critical structure in maintaining uterine support, and their damage or weakening can lead to uterine prolapse. It's essential to recognize the importance of these ligaments in pelvic floor anatomy.

**Correct Answer: C. Uterosacral ligaments.**