Why is water from an aquifer more likely to be cleaner than water from other sources? A. because it forms where fresh and salt water meet B. because it receives water directly from precipitation C. because it rises to the surface near the ocean D. because pollutants are filtered by rock and soil deep within Earth

The answer is D. because pollutants are filtered by rock and soil deep within Earth.

Here's the step by step explanation:

1. An aquifer is a body of permeable rock which can contain or transmit groundwater.

2. When water from precipitation seeps into the ground, it can eventually reach an aquifer.

3. As the water travels through the soil and rock, many of the pollutants it carries are naturally filtered out. This is due to the physical process of filtration where the water passes through small gaps in the soil and rock, and the pollutants are trapped.

4. By the time the water reaches the aquifer, it has been significantly cleaned by this natural filtration process.

5. Therefore, water from an aquifer is often cleaner than water from other sources because it has been naturally filtered by the rock and soil deep within the Earth.