Answer:
B
Explanation:
As you move down the periodic table in the carbon family, the atomic radius and ionic radius increase while electronegativity and ionization energy decrease. Atom size increases moving down the group because an additional electron shell is added.
Li2O
Fe(NO3)3
Al2O3
CuCl2
ZnSO4
All you have to do here is make sure your charges are balanced when you write the compound. For example, Iron (III) has a +3 charge, and nitrate has a -1 charge. You need 3 nitrates to match that charge, hence Fe(NO3)3.
Here are the resonance contributors I found.