Answer:
D. conduct electricity.
Step-by-step explanation:
Delocalized electrons are electrons that are not associated with any atom or ions. These electrons differ from localized electrons which associates with a particle. Localized electrons for example are the ones transferred between ions when ionic bonds form and are shared when covalent bonding occurs.
The sea of delocalized electrons found in crystals helps in electric conduction in most metals we have. The electrons are free and mobile and not attached to any atom. This makes them readily available for electrical conduction.