Which of the Following Statements Is True

Which of the following statements is true?

A) Magnesium is a conductor of electricity, because the filled 3s valence band overlaps the vacant 3p conduction band, and this allows it to be easily populated with electrons when a voltage is applied.
B) Metallic sodium is a good conductor of electricity because the valence band is quite different from the conduction band.
C) Calcium metal is a good conductor of electricity because the band gap is fairly large.
D) Germanium is a weak conductor of electricity because the valence band is filled with electrons and these are the electrons normally used to form covalent bonds.
E) In silicon, which is a semiconductor, the band gap between the valence band and the nearest conduction band is large, but the thermal energy possessed by electrons is sufficient to promote some to the conduction band.