Which of the following bones is known as the collarbone?

The clavicle is commonly referred to as the collarbone due to its location and function in the skeletal system. It is a long bone that connects the arm to the body, specifically linking the scapula (shoulder blade) to the sternum (breastbone) at the front of the ribcage. This positioning creates a recognizable bilaterally symmetrical structure across the upper chest, which is why "collarbone" is a familiar term used to describe it.

The clavicle plays a crucial role in providing support for the shoulder, allowing for a wide range of motion in the arm. It also serves as an important attachment site for muscles of the shoulder and neck, helping to stabilize the upper limb. This anatomical relationship underscores its significance in both function and movement, solidifying its identity as the collarbone.

Other bones listed, such as the sternum, scapula, and radius, have distinct anatomical features and functions that do not correspond to the term "collarbone." The sternum is located centrally in the chest, the scapula is the flat bone that connects with the clavicle and forms part of the shoulder girdle, and the radius is one of the two forearm bones responsible for movement of the hand and wrist.