This question is answered with respect to following attached graph.
Answer: T<span>he solubility of <u>NaCl</u> is least affected by temperature.
Explanation: When any solute is dissolved in water it either releases heat (Exothermic Reaction) or absorbs heat (Endothermic Reaction). This heat absorbed or released is called as Heat of Solution. Heat of solution depends upon heat of ionization (endothermic process) and heat of hydration (exothermic process). When heat of ionization is greater than heat of hydration then the reaction will be endothermic and vice versa. In case of NaCl the heat of Ionization and Heat of Hydrations are almost same. That is why the solubility of NaCl is least effected by temperature.</span>