Answer: Choice C) A river runs through the canyon, causing weathering and erosion of rocks to make the canyon even deeper.
Imagine taking a hose and spraying at a dirty piece of wood. Some or all of the dirt will come off from the water colliding into the dirt particles. Imagine that applied to the rocks and earth. Over a long period of time, the water will carve a path and a river will form. In this case, it carved a very deep canyon over the many millions of years that have elapsed.
