because it forms where fresh and salt water meet because it receives water directly from precipitation because it rises to the surface near the ocean because pollutants are filtered by rock and soil deep within Earth
I gave my students this multiple choice question: Why is water from an aquifer more likely to be cleaner than water from other sources?

Only one answer is correct among these 4 choices:
- because it forms where fresh and salt water meet
- because it receives water directly from precipitation
- because it rises to the surface near the ocean
- because pollutants are filtered by rock and soil deep within Earth

Could you tell me which one is correct?

because pollutants are filtered by rock and soil deep within Earth