What Property of the Crust Allowed It to Form as the Exterior

Multiple Choice

What property of the crust allowed it to form as the exterior of Earth?

A) Magma at the surface cooled and crystallized before anything in the interior.
B) Materials that make up the crust are less dense and rose to the top.
C) Churning and upheaval in the interior thrust crustal rocks toward the surface.
D) Meteorites impacting Earth deposited this material at the surface.