Mercury Has a Higher Proportion of Iron in Its Makeup

Mercury has a higher proportion of iron in its makeup than does Earth. So how does Mercury's density compare to Earth's density?

A) Mercury must have the higher density.
B) Earth has the greater density because larger masses always have greater densities.
C) Mercury has the smaller density because the non-iron portion of its makeup is very light, porous materials that more than compensate for the greater proportion of iron.
D) Earth has the greater density because Earth's iron is more dense than Mercury's iron, thanks to the greater pressure experienced at the core of Earth compared to that at Mercury's core.