The value of ∆H° for the following reaction is -3351 kJ: 4Al(s) + 3O₂(g) --> 2Al₂O₃(s).
The value of ∆Hf° for Al₂O₃(s) is ______ kJ.
a) -16.43
b) 0
c) 3351
d) -3351