Which of the following is NOT a muscle of the lower leg?

The choice of C is accurate because the Biceps Femoris is not a muscle located in the lower leg; rather, it is part of the hamstring group, which is situated in the upper leg or thigh. This muscle is responsible for bending the knee and extending the hip.

On the other hand, the muscles listed in the other options—such as Flexor Digitorium, Peroneus Longus, and Soleus—are all located in the lower leg. The Flexor Digitorium aids in flexing the toes, the Peroneus Longus plays a key role in foot eversion and stabilization, and the Soleus contributes significantly to the movement of the ankle and is essential for activities like walking and running. These distinctions clarify why the Biceps Femoris is not considered a muscle of the lower leg.