Which bone lies between the scapula and radius?

The correct answer is the humerus. The humerus is the long bone of the upper arm and is situated between the scapula (shoulder blade) and the radius (one of the two bones in the forearm). The humerus connects to the scapula at the shoulder joint and to the radius at the elbow joint, establishing a functional relationship between the upper arm and the forearm. This anatomical positioning is essential for various movements of the arm, as it acts as a lever for muscle attachment and allows for a range of shoulder and elbow motions.

The other options represent bones that do not fit the anatomical relationship described in the question. The tibia is a bone in the lower leg, and the ulna is a forearm bone located alongside the radius, but it is not situated between the scapula and radius in the way the humerus is. The central tarsal bone pertains to the ankle region and is unrelated to the arm's anatomy.