Answer: the canola oil.
Explanation:
According to the melting points reported, at 5°C canola oil, whose melting point is 10°C, will freeze (become solid), while the other three, corn oil, sunflower oil, and peanut oil, having melting points several degrees below 5°C, will remain in liquid state.
Therefore, by decantation or filtration, which are processes that permit separate solids from liquids in a mixture, you can separate easily the solid canola oil from the other three liquid oils.
After separating the canola oil, If you continue cooling the mixture and reach a temperature of - 5°C. the peanut oil, whose melting point is -2°C, whill freeze and you will be able to separate it (again by decantation or filtration).
The same operation, cooling a third time until a temperature around 12°C, will permit you to separate the remaining two oils.
As you see, the knowledge of the physical properties of the substances is a useful tool to separate mixtures.
