The correct answer is - E) chemical pollution.
The waterways can be influenced by both, nature and the human activities. While the mother nature has lots of influence on the waterways in multiple different ways, the human activity seems to have even more attributes at its sleeves. The humans create a lot of pollution, and the water suffers a lot from it, thus the waterways as well, and one of these pollution types is the chemical one. The chemical pollution comes from the manufactures chemicals or chemical waists that go into the water. They change the composition of the water, its biosphere, its functioning, and as an end consequence comes the change of the waterways as well.