Final answer:
The restoring force is what causes a spring to return to its original shape after being stretched, in accordance with Hooke's law.
Step-by-step explanation:
The force that restores the spring to its original shape after Maurice lets go of the end of a spring scale is called the restoring force. When the spring is stretched, it stores potential energy, which is then released as it snaps back into place, exerting this restoring force. According to Hooke's law, the restoring force is proportional to the displacement from the equilibrium position, in the opposite direction of the displacement. This is what causes the spring to return to its original length when released. Gravity, friction, tension, and magnetism are other forces that could act on objects but in the context of returning a spring to its original shape, it is the restoring force that is responsible.