Besides air pollution, the student was concerns about water/ocean pollution. They heard many recent issues of too much plastic in the ocean and other pollutants in the water. The pie chart below provides data on the sources and amounts of different pollutants entering the oceans. first picture

The student read a news article that discussed the increase in amount of pollutants entering oceans and washing up on shores. The article included this image.
second picture

pick the answer

The greatest reduction in pollutants entering the ocean could be achieved if it were possible to reduce farm runoff/transportation/air pollutants/sewage/litter/ orindustry waste.