The correct option is C C - F
∙ Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons. The polar character depends on the electronegativity difference of the constituent atoms.
∙ Since, carbon (C) is common among all options hence, the polar character of molecules will depend on the electronegativity of other atoms.
∙ Fluorine is the most electronegative element. Hence, maximum electronegativity difference is seen in carbon and fluorine (C - F). Thus, the C-F bond has the most polar character.