MOST of the Craters on the Moon Were Formed By

MOST of the craters on the Moon were formed by:

A) water erosion, followed by evaporation early in the Moon's history, leaving behind the empty basins, the maria, and craters.
B) a nuclear war in which the lunar inhabitants wiped themselves off the face of the Moon.
C) bombardment by interplanetary meteoritic material.
D) volcanic action; the craters are the old calderas of volcanoes.