The Quadriceps Femoris includes which of the following muscles?

The Quadriceps Femoris is a major muscle group located at the front of the thigh, primarily responsible for knee extension. It consists of four muscles: the Rectus Femoris, Vastus Lateralis, Vastus Medialis, and Vastus Intermedius. The Rectus Femoris is one of these four muscles and contributes not only to knee extension but also plays a role in hip flexion due to its origin on the pelvis.

The other options listed are not part of the Quadriceps Femoris. The Sartorius is a long, thin muscle that acts as both a hip flexor and knee flexor but does not contribute to the quadriceps group. The Gracilis is a muscle that lies on the inner thigh and is involved in adduction of the hip and flexion of the knee. The Adductor Longus is primarily responsible for adducting the thigh and also lies in the inner thigh region, not contributing to the Quadriceps Femoris.

Thus, the inclusion of the Rectus Femoris is essential to the definition of the Quadriceps Femoris group, making it the correct answer.