What property of matter allows a body to return to its original shape after deformation?

The property of matter that allows a body to return to its original shape after deformation is elasticity. When a material is subjected to stress such as stretching or compressing, it may temporarily change its shape. However, if the material is elastic, it will return to its original shape once the stress is removed. This property is crucial in many real-world applications, such as in rubber bands, springs, and various materials used in engineering and manufacturing.

In contrast, plasticity refers to a material's ability to undergo permanent deformation when a stress is applied, meaning that once the stress is removed, the material will not return to its original shape. Rigidity refers to a material's resistance to deformation; rigid materials do not easily change shape under stress, and thus they are not defined by their ability to return to a previous shape. Fluidity describes how easily a substance can flow; fluids can change shape but do not have a fixed structure to return to, which is unrelated to the concept of returning to an original shape after deformation. Therefore, elasticity is the correct property that defines materials capable of returning to their original form after being deformed.