**Core Concept**
The quadriceps femoris muscle is responsible for knee extension and stabilization of the patella. However, there are anatomical structures that prevent excessive hyperextension of the thigh, particularly at the hip joint.

**Why the Correct Answer is Right**
The iliofemoral ligament (or the Y-ligament), also known as the ligament of Bigelow, is a strong fibrous ligament that connects the ilium to the femur. It acts as a natural stabilizer of the hip joint and prevents excessive hyperextension of the thigh, thereby maintaining the normal range of motion. This ligament plays a crucial role in stabilizing the hip joint and preventing dislocation.

**Why Each Wrong Option is Incorrect**
* **Option A:** The gluteus maximus muscle primarily functions as an extensor of the hip joint, not a stabilizer against hyperextension.
* **Option B:** The iliopsoas muscle is a flexor of the hip joint, not a stabilizer against hyperextension.
* **Option D:** The piriformis muscle primarily functions as a stabilizer of the hip joint, but not specifically to prevent hyperextension.

**Clinical Pearl / High-Yield Fact**
The iliofemoral ligament is often referred to as the strongest ligament in the human body, with a tensile strength of up to 3,500 pounds per square inch (psi).

**Correct Answer:** C. The iliofemoral ligament prevents hyperextension of the thigh.