Which of the following describes a fibrous joint?

A fibrous joint is characterized by the absence of a joint cavity and the presence of fibrous connective tissue that firmly binds the bones together. The sutures of the skull are a prime example of this type of joint. They are immovable joints where the edges of the skull bones interlock, providing structural stability and protection for the brain.

In contrast, joints connecting the spine are primarily classified as cartilaginous joints, which allow for limited movement. The joints of the wrist are synovial joints, which are highly mobile and characterized by the presence of a joint capsule filled with synovial fluid. Lastly, the joints between the upper and lower leg (such as the knee) are also synovial joints, allowing for a wide range of motion. Therefore, the sutures of the skull are accurately described as fibrous joints due to their nature and the way they connect the bones without allowing movement.