Concept:The cooling effect is caused by rapid evaporation removing heat from the skin.Explanation:Ether evaporates very quickly at room temperature.This happens because ether has a low latent heat of vaporization.A small amount of heat is enough to convert it into vapour.The heat required for evaporation is taken from the hand.As the hand loses heat, it feels a cooling effect.Answer:D. low latent heat of vaporization