Final answer:
Dipole-dipole interactions are the strongest intermolecular forces in CH₃Cl.
Step-by-step explanation:
The strongest intermolecular forces in CH₃Cl are dipole-dipole interactions. Dipole-dipole forces arise from the electrostatic interactions between the positive and negative ends of polar molecules. CH₃Cl is a polar molecule because the chlorine atom is more electronegative than the carbon and hydrogen atoms, resulting in an unequal distribution of electrons and a partial positive charge on the hydrogen atoms and a partial negative charge on the chlorine atom.