In order to separate oil and water, there are many options to do so, you could use their differences in boiling point, and also their differences in density, and this last one is considered to be the best way to separate oil from water, since water is denser than oil, they will form two distinct layers in a container, and they can easily be separated. This method can also be called decantation. Letter C. But it is important to have in mind, it is NOT the only possible method.