Answer
D. It keeps chemicals from entering the watershed
Explanation
Agricultural run off can be described as the disposal of artificial fertilizers , pesticides, herbicides, sewages etc into which drained off into oceans , lakes and ponds with water .
Agricultural run off is recycled , then water will be less polluted , the water therefore be not harmful for usage by the plants/crops & it will make the drained water less contaminated for the Aquatic living in the ocean , rivers , lakes or ponds
