When ionic substances/electrolytes are dissolved in water, they dissolve and increase the conductivity of water. The conductivity of electrolytes is dependent on various factors just like conductivity of metal solids. The various factors include nature of the electrolyte added, size of their ions produced and solvation, which is the interaction of the solute molecules with solvent, the nature of the solvent and its viscosity, concentration of the electrolyte, and temperature of the solution. Conductivity does depend on the solvation of ions due to the interaction of solute-solvent molecules. The correct answer is (iii).