Answer:
D
Explanation:
Islam is the dominant religion in North Africa and the Horn of Africa.
They have a characteristic U shape, with steep, straight sides and a flat or rounded bottom (by contrast, valleys carved by rivers tend to be V-shaped in cross-section). Glaciated valleys are formed when a glacier travels across and down a slope, carving the valley by the action of scouring.
Water IS capable of carving the Grand Canyon. The river in the middle of the canyon eroded the ground and, over millions of years, deepened the Canyon to the one we know today. The reason it doesn't seem to be deepening is because it takes a very, VERY long time.
Hope this helps!