Which of the following reasons support that arylhalides are less...

The correct reasons why aryl halides are less reactive than alkyl halides towards nucleophilic substitution are (\mathrm{b}) and (\mathrm{d}). - b) Partial double bond character of C-X bond: Due to resonance, the lone pair on the halogen atom is delocalized into the benzene ring, creating a partial double bond character between the carbon and the halogen. This makes the C-X bond shorter and stronger than in an alkyl halide, thus harder to break. - d) $s p^2$ carbon bonded to X is more electronegative: The carbon atom in an aryl halide is $s p^2$ hybridized, which has more s-character ((33 \%)) than the $s p^3$ hybridized carbon in an alkyl halide (25%). This makes the $s p^2$ carbon more electronegative and able to hold the shared electron pair more tightly. Consequently, the carbon-halogen bond is stronger and less susceptible to nucleophilic attack.