Which one of the following is most soluble in water?

a, the shorter the carbon chain, the more soluble it is in water. As the carbon chain increases, the -OH (alcohol) bonds play a smaller and smaller role in the molecule. Therefore, the solubility decreases with increasing size. The only reason these substances dissolve in water is because they are able to form hydrogen bonds with H2O. As the OH ending becomes less prominent with increasing carbon chain, the solubility decreases. So the answer is a because it is the most soluble (least amount of carbons). For comparison, e is the least soluble.