Which of the following is an example of a pivot joint?

A pivot joint allows for rotational movement around a single axis and primarily enables one bone to rotate around another. The neck, specifically the atlantoaxial joint located between the first and second cervical vertebrae (the atlas and axis), is a prime example of a pivot joint. This joint permits the head to turn from side to side, facilitating rotation.

In contrast, other options represent different types of joints. The elbow is a hinge joint, enabling flexion and extension; the knee functions primarily as a hinge joint but also allows for a small degree of rotation; and the wrist is composed of multiple joint types, including gliding and ellipsoidal joints, providing a wider range of motion than a pivot joint. Understanding the specific functions and structures of these joints can help clarify why the neck is categorized as a pivot joint.