Which of the following makes up the lower extremities?

The lower extremities of the human body consist of the segments and bones that are involved in locomotion and support, primarily associated with the legs. The correct answer includes the femur, tibia, and fibula, which are the major bones that comprise the thigh and the lower leg.

The femur, or thigh bone, is the longest bone in the body and connects the hip to the knee. The tibia, commonly referred to as the shinbone, is the larger and stronger of the two bones in the lower leg and bears most of the weight. The fibula runs alongside the tibia and, although it is smaller and does not bear much weight, it serves as an important structure for muscle attachment and provides stability to the ankle.

In contrast, the other choices refer to upper body components or different areas of the skeleton. The humerus and radius are bones of the upper extremities (the arms), while the cervical vertebrae are part of the spinal column in the neck. The scapula and clavicle are components of the shoulder girdle, also associated with the upper body. Therefore, the inclusion of the femur, tibia, and fibula correctly identifies the anatomical components constituting the lower extremities.