Question

What is the leading cause of water pollution in the United States? a. point source pollution b. nonpoint source pollution c. lack of regulation d. none of the above

Answer 1

"Much of this runoff flows to the sea, carrying with it agricultural fertilizers and pesticides. Eighty percent of pollution to the marine environment comes from the land. One of the biggest sources is called nonpoint source pollution, which occurs as a result of runoff."
So I'll conclude by picking b. Nonpoint source pollution.

Answer 2

Answer: b. non point source pollution

The leading cause of water pollution in the United States is the non-point source pollution. A non- point source pollution is cause by the discharge of pollutants from the sources whose origin cannot be traced back. The main source of non-point source pollution is rainfall and surface runoff, which get mixed with a water body carrying the contaminants along with it. The reduction of such pollutants from the water cannot be done as the source is undetermined.