The question asks: **When a structure is subjected to stress, the irrevocable deformation that remains in that structure is,** The options are: - Resilience - Ductility - Permanent Set - Plasticity **Correct Answer:** **Permanent Set** **Explanation:** "Permanent set" refers to the deformation that remains in a material after the load causing the deformation has been removed. It is the non-recoverable, irreversible deformation, unlike elastic deformation, which is recovered when the stress is removed. - **Resilience** is the ability to absorb energy and return to its original shape. - **Ductility** is the ability to deform plastically before fracturing. - **Plasticity** is the property that allows permanent deformation, but the specific remaining deformation is called "permanent set." So, the correct answer is **Permanent Set**.