C) Plant trees and native plants along the river.
This solution can help stabilize the soil along the river banks, reduce erosion, and provide habitat for wildlife. Trees and native plants have deep root systems that can hold the soil in place, preventing it from washing away during heavy rains and flooding. Additionally, the vegetation can absorb excess water and slow down the flow of the river, further reducing erosion. This natural approach can also enhance the beauty of the area and improve water quality by filtering pollutants.