c. pesticide runoff. Point source pollution is a kind of pollution that comes from a specific place (when the contaminants come from a single location). Example: operational wastes from industries. Non-point-source pollution results when contaminants are introduced into the environment over a large, widespread area. Example: Pollutants are absorbed by plants so then the plants become toxic as well (soil).
Runoff is the movement of water and any contaminants across the soil surface (occurs when irrigation or rain adds water to a surface faster than it can enter the soil). And the pesticides can move with the runoff water.