Which source of water is beneath the earth’s surface and influenced by surface runoff?

Groundwater is the correct answer because it refers to water that is stored beneath the earth's surface in soil pore spaces and fractures of rock formations. This type of water is influenced by surface runoff, which occurs when rain or melting snow flows over land and can seep into the ground, replenishing the aquifers that constitute groundwater. This process allows water from rainfall and surface streams to infiltrate through the soil and into underground reservoirs, highlighting how surface water can affect the levels and quality of groundwater supply.

Rainwater, while it falls from the sky, is not categorized specifically as an underground source and does not remain beneath the surface itself. Surface water refers to bodies of water such as rivers, lakes, and ponds that are visible on the land's surface and do not exist underground. Atmospheric water typically indicates moisture in the air, including water vapor, rain, or snow, but it also does not describe water stored beneath the earth's surface. Understanding these distinctions helps clarify why groundwater is the most accurate response to the question posed.