using a paper filtering system using chromatography allowing the salt to settle allowing the water to evaporate
I gave my students this multiple choice question: Which of these will best separate a saltwater solution?

Only one answer is correct among these 4 choices:
- using a paper filtering system
- using chromatography
- allowing the salt to settle
- allowing the water to evaporate

Could you tell me which one is correct?

allowing the water to evaporate