Correct Answer: Agricultural runoff

Solution : The correct answer is (d) Agricultural runoff

Non-point source pollution refers to the contamination of water bodies, soil, or air from diffuse sources that cannot be traced back to a single, identifiable source. It occurs when pollutants, such as fertilizers, pesticides, and sediment, are carried by runoff from agricultural fields and other areas without a specific discharge point. This runoff can enter rivers, lakes, and groundwater, causing pollution and ecological damage. In contrast, options a) Industrial discharge, b) Sewage treatment plant effluent, and c) Oil spill from a tanker are examples of point source pollution where pollution can be traced back to specific discharge points.