Which bonds cause the strongest intermolecular forces and why?

Question

Ionic bonds because of the large difference in electronegativity of the two atoms.
Covalent bonds because the atoms in a covalent bond are very close to each other. .
Ionic bonds because metals have a higher electronegativity than nonmetals.
Covalent bonds because they create strong dipoles in polar molecules.

Answer 1

The correct answer is: Ionic bonds because of the large difference in electronegativity of the two atoms.