Anhydrous Aluminum Oxide Is Dissolved in Molten Cryolite Rather Than

Anhydrous aluminum oxide is dissolved in molten cryolite rather than simply melted because
__________

A) the cryolite provides a source of sodium ions.
B) the melting point of pure, anhydrous aluminum oxide is too high.
C) the cryolite provides the necessary fluoride ions.
D) the cryolite actually provides the aluminum that is to be reduced.
E) in pure, molten Al₂O₃, the aluminum would be oxidized rather than reduced.