According to the Band Theory, Which of These Statements Provide(s)

Multiple Choice

According to the band theory, which of these statements provide(s) an explanation for the high electrical conductivity of metals
I. a partly filled conduction band
II. a valence band overlapping an empty conduction band
III. a filled valence band
IV. a large gap between the valence band and the conduction band

A) I and II
B) I and III
C) III
D) III and IV
E) IV