The salt which will give a neutral solution on dissolving in water will be:
KCl is formed from a strong acid, hydrochloric acid (HCl), and a strong base, potassium hydroxide (KOH). On dissolving in water, KCl hydrolyses to form equal amounts of H+ and OH- ions. This is why an aqueous solution of KCl is neutral with a pH of almost 7.
Lakhmir Chemistry 2013