Explanation:

- The human shoulder joint is an example of a ball and socket joint.

- Ball and socket joints allow for movement in many directions. This joint type enables the shoulder's wide range of motion.

- Fixed joints (Option 1) are immovable. They consist of bones that are fused together, like the skull bones.

- Pivotal joints (Option 2) allow rotation around a single axis, like the neck joint.

- Hinge joints (Option 3) only allow movement in one direction, similar to a door hinge, found in knees and elbows.

Correct Answer: Option 4 - Ball and Socket