Which of the following defines a point source of pollution?

A point source of pollution is defined as a specific location from which pollution is discharged. This can be thought of as a single identifiable source that releases contaminants into the environment, typically a fixed, localized site such as a pipe, a drain, or a factory outlet. The key characteristic of a point source is its identifiable nature, making it easier to monitor and regulate compared to diffuse sources, which can be spread out over a larger area and involve contributions from multiple sources.

When considering the other options, diffuse sources of contamination refer to non-specific and widespread sources of pollution, such as agricultural runoff or urban stormwater runoff, where contaminants enter the environment without a clear point of origin. Direct runoff into water bodies might relate to pollution, but it does not specify that it emanates from a single point location. The spread of pollutants in the air refers to airborne contaminants which can come from various sources but do not represent a singular point source. Therefore, the definition of point source pollution aligns perfectly with the idea of a specific location of contamination.