To Explain the Large Iron Core of Mercury, One Theory

Multiple Choice

To explain the large iron core of Mercury, one theory suggests that as Mercury was forming as a planet it was struck by a large planetesimal, stripping away the mantle and leaving the iron core. This theory has the advantage because it also helps to explain Mercury's:

A) 3-to-2 spin-orbit coupling.
B) highly elliptic orbit.
C) Caloris Basin.
D) slow rotation rate.