Why Do Lunar Scientists Think the Surface of the Moon

Multiple Choice

Why do lunar scientists think the surface of the moon was once a magma ocean?

A) The lunar highlands contain large amounts of the rock anorthosite,which is the light material that "floated" on the top of the magma ocean.
B) The surface of the moon is entirely volcanic.
C) Early lunar craters show a morphology suggesting impact with a liquid.
D) None of these is correct.