What is the strongest intermolecular force that occurs between molecules of CO2?

The strongest intermolecular force that occurs between molecules of CO2 (carbon dioxide) is London dispersion forces.

CO2 is a nonpolar molecule, and while it does not have permanent dipoles (and therefore does not exhibit dipole-dipole interactions), it can still have induced dipoles due to the fluctuations in electron distribution. These induced dipoles give rise to London dispersion forces, which are present in all molecular interactions, but are the primary force in nonpolar molecules like CO2.

So, the correct answer is **London dispersion**.