Correct Answer: Agricultural runoff

Solution : The correct answer is (D) Agricultural runoff.

Non-point source pollution refers to the pollution that does not originate from a single, identifiable source. It occurs when pollutants are carried into water bodies through runoff from diffuse sources, such as agricultural fields, urban areas, and natural landscapes. These sources are characterized by widespread and scattered pollutant inputs, making it challenging to trace the exact origin of the pollution.

Among the options provided, agricultural runoff best represents a non-point source of water pollution. When rainfall or irrigation water runs off agricultural fields, it can carry various pollutants, including fertilizers, pesticides, sediment, and animal waste, into nearby water bodies. These pollutants can degrade water quality, harm aquatic ecosystems, and negatively impact human health.