Question

Identify the intermolecular force, or forces that predominate in Al2O3 (check all that apply)

Group of answer choices

1. ionic

2. H-bonding

3. dispersion

4. dipole dipole

Answer 1

You are calling these a "group of" answer choices but what you have listed are not groups but single answer choices.
If we call a difference of 1.7 the 50-50 ionic/covalent bond for electronegativity (EN), then this is more ionic than covalent (delta EN = 1.9) so ionic is one, dipole-dipole is another. There are no H bonds. There are dispersion forces in anything but dispersion forces are weak so I wouldn't count those as predominate.