The Best Method for Estimating the Age of the Surface

The best method for estimating the age of the surface of a celestial body with a solid surface such as a terrestrial planet or a moon (other than bringing rock samples back to Earth) is based on the idea that:

A) volcanic activity occurs at a known rate, so the fewer volcanoes observed, the younger the surface.
B) planets and other bodies are subject to impacts from space at a known rate, so the fewer the number of craters, the younger the surface.
C) lithospheric plates form at a known rate, so the more plates observed, the older the surface.
D) craters are weathered at a known rate, so the more eroded the craters, the older the surface.