The surface of the earth is not level although weathering and erosion have been

The surface of the earth is not level although weathering and erosion have been occurring for millions of years which is the best explanation of this observation

A. The sea level keeps changing.
B. Movements in the earth's surface continue to occur.
C. There has not been enough time.
D. Wind and water erosion are not strong enough.
E. Glacier movement is required to smooth the earth's surface.