What structures are formed when water molecules surrounds individual ions?

Ions are stabilized by a layer of water molecules that surround it. This is known as solvation or hydration of the ions. A water molecule has a dipole, where the more electronegative O atom has a partial negative charge and the H atom has a partial positive charge. Cations (positively charged ions) are surrounded by the negative dipole of the water molecule and the anions (negatively charged ions) are surrounded by the positive dipole of the water molecule.

A lattice structure is formed when water molecules surrounds individual ions.

the answer is definitely c.