**Core Concept**
The inguinal ligament is a fibrous band that plays a crucial role in the anterior abdominal wall, providing support to the lower abdominal organs and the inguinal canal. It is a significant anatomical landmark in the region of the hip and groin.

**Why the Correct Answer is Right**
The inguinal ligament forms the floor of the inguinal canal and serves as a boundary between the abdominal wall and the thigh. It runs from the anterior superior iliac spine (ASIS) to the pubic tubercle, thereby creating the base of the inguinal canal. This ligament is a vital structure for the proper functioning of the inguinal canal, which allows the spermatic cord in males and the round ligament of the uterus in females to pass through.

**Why Each Wrong Option is Incorrect**
**Option A:** The inguinal ligament is not a boundary of the femoral triangle. The femoral triangle is a region of the thigh bounded by the inguinal ligament, the sartorius muscle, and the medial border of the adductor longus muscle.
**Option B:** The inguinal ligament does not form the boundary of the psoas major muscle. The psoas major muscle is located deep to the inguinal ligament and runs from the lumbar spine to the femur.
**Option C:** The inguinal ligament is not a boundary of the femoral artery. The femoral artery is located deep to the inguinal ligament and passes through the femoral triangle, which is bounded by the inguinal ligament.

**Clinical Pearl / High-Yield Fact**
The inguinal ligament is a significant landmark in inguinal hernia repair, and its identification is crucial for accurate dissection and repair of the hernia. The ligament serves as a guide for the inguinal canal and helps surgeons to identify the correct planes for repair.

**Correct Answer: C. The femoral triangle**