The Reason That Worlds Like the Earth Are Differentiated Is

Multiple Choice

The reason that worlds like the Earth are differentiated is that

A) the heat of the Sun vaporized much of their solid material early on
B) the heaviest chunks that hit early on were able to bore through solid rock to the center
C) the continuing impacts on a growing protoplanet eventually melted the entire body
D) large amounts of hydrogen and helium collect around such planets a little later in their history
E) planetesimals with different types of composition hit at different times, with the heaviest ones hitting first