All of them,
Kool-Aid- when you pour the Kool-Aid into water, the little crystals go straight to the bottom because they are heavier than the water. When you stir Kool-Aid, you help dissolve the Kool-Aid in water by keeping all the crystals off the bottom and in the water.
Salt- water can dissolve salt because the positive part of water molecules attract the negative chloride ions and the negative part of water molecules attracts the positive sodium ions.