The terrestrial planet cores contain mostly metal because?

Question

radioactivity created metals in the core from the decay of uranium.
convection carried the metals to the core.
metals sank to the center during a time when the interiors were molten throughout.
metals condensed first in the solar nebula and the rocks then accreted around them.
the entire planets are made mostly of metal.

Answer 1

metals sank to the center during a time when the interiors were molten throughout

Answer 2

D. convection carried the metals to the core. "Formation of the Earth's Core Once the proto-Earth had aggregated, internal heat from radioactive decay, combined with gravitational energy and collisional energy from planetesimal bombardment kept the planet molten. As the proto-Earth cooled, reduction reactions within the CONVECTING SYSTEM resulted in production of a metal-rich core and a silicate-rich crust-mantle structure."

Answer 3

Yes to the above:)

It's called differentiation. (the whole process)