The correct answer is option 1: Leachates. Leachates are pollutants that move downward with percolating (filtrating) groundwater. Leaching occurs when water passes through soil or other permeable materials and carries dissolved substances with it. This process can cause the pollutants to penetrate into the groundwater, potentially contaminating it. Examples of leachates include chemicals from agricultural practices, industrial waste, or landfill sites. The term "pollutates" is not commonly used and does not accurately describe pollutants that move downward with groundwater. Similarly, "earthites" is not a recognized term in environmental science. Option 4, "percolates," does describe the movement of substances through the soil, but the pollutants themselves are specifically referred to as leachates in this context.