The Internal Structure of Mercury Is A

The internal structure of Mercury is a:

A) dense iron core taking up almost half of the volume of the planet and a rocky mantle surrounding the core.
B) rocky core with a liquid (or perhaps frozen) water mantle and icy surface.
C) thick rocky mantle taking up most of the volume of the planet, overlaying a small but dense iron core.
D) rocky core surrounded by liquid metallic hydrogen and a hydrogen-helium atmosphere.