Which Would You Expect to Have a Higher Melting Point

Multiple Choice

Which would you expect to have a higher melting point: sodium chloride, NaCl, or aluminum oxide, Al₂O₃?

A) The aluminum oxide has a higher melting point because it is a larger molecule and has a greater number of molecular interactions.
B) NaCl has a higher melting point because it is a solid at room temperature.
C) The aluminum oxide has a higher melting point because of the greater charges of the ions, and hence the greater force of attractions between them.
D) The aluminum oxide has a higher melting point because of the covalent bonds within the molecule.