Distinguish between the holoenzyme and the core enzyme.
a) Holoenzyme: activated form of an enzyme; Core enzyme: inactive form
b) Holoenzyme: inactive form of an enzyme; Core enzyme: activated form
c) Holoenzyme: complete enzyme with its cofactor; Core enzyme: enzyme without cofactor
d) Holoenzyme: enzyme without its cofactor; Core enzyme: complete enzyme with its cofactor