You are presented with the quiz "What can be added to a liquid to decrease the melting point of the liquid?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "adding salt to a liquid decreases the melting point of that liquid" and "salt particles come from the ocean as the spray of waves evaporates, leaving salt particles suspended in the air". 

So, what's the best answer to the question?


 

        Something from an ocean   