In the Rolling Plains ecoregion of Texas, some parts of rivers are in deep canyons and others have bottoms that are close to the level of the surrounding land. What conditions are most likely to be found in a place where a canyon has formed?
A. fast-moving water and rock that is easily eroded
B. slow-moving water and rock that is highly resistant to erosion
C. slow-moving water and rock that is easily eroded
D. fast-moving water and rock that is highly resistant to erosion