That the Tharsis Region on Mars Has So Few Craters

Multiple Choice

That the Tharsis region on Mars has so few craters:

A) proves tectonic activity is taking place.
B) is due to the regions very low elevation.
C) suggests it is the youngest region on the planet.
D) suggests it is at the center of a particularly strong magnetic field.
E) is due to annual flooding and water erosion.