**Core Concept**
The ovarian ligament is a fibrous structure that connects the ovary to the uterus in the female reproductive system. It plays a crucial role in the support and positioning of the ovary within the pelvic cavity.

**Why the Correct Answer is Right**
The ovarian ligament arises from the lateral angle of the uterus, specifically from the lateral margin of the uterine horn or uterine body in the case of a unicornuate uterus. It then extends laterally to attach to the ovary, providing a fibrous connection between the two organs. This ligament is distinct from the suspensory ligament of the ovary, also known as the infundibulopelvic ligament, which connects the ovary to the pelvic wall. The ovarian ligament's primary function is to maintain the ovary's position within the pelvic cavity, ensuring optimal blood supply and nerve innervation.

**Why Each Wrong Option is Incorrect**
**Option A:** The mesovarium is the fold of peritoneum that connects the ovary to the broad ligament of the uterus, not the ovarian vessels. It does not contain ovarian vessels.
**Option C:** The ovarian fossa is a shallow depression on the lateral wall of the pelvis, bounded by the external iliac artery and vein, and the ureter. It is related to the ovary, but not directly associated with the ilioinguinal nerve.
**Option D:** The suspensory ligament of the ovary, also known as the infundibulopelvic ligament, connects the ovary to the pelvic wall, not the uterus. It provides additional support to the ovary and contains ovarian vessels.

**Clinical Pearl / High-Yield Fact**
The ovarian ligament is a critical anatomical landmark in gynecological surgery, particularly during ovarian cystectomy or oophorectomy procedures. It is essential to identify and preserve this ligament to maintain the ovary's blood supply and prevent postoperative complications.

**✓ Correct Answer: B. Ovarian ligament connects ovaries to uterus**