Which of the following bones is NOT part of the upper appendicular skeleton?

The fibula is the correct answer because it is a bone located in the lower limb and is part of the lower appendicular skeleton. The fibula runs parallel to the tibia and helps to stabilize the ankle, but it does not contribute to the structure of the upper appendicular skeleton.

In contrast, the clavicle, scapula, and humerus are all integral components of the upper appendicular skeleton, which includes the bones that make up the shoulder girdle and the upper limbs. The clavicle serves as a strut between the sternum and scapula, the scapula connects with the humerus at the shoulder joint, and the humerus is the long bone of the upper arm, facilitating arm movement. Understanding the functions and locations of these bones helps clarify their roles in the skeletal system and their classification within the appendicular skeleton.