This
answer is not correct. This is a good answer if you only think of
hyperconjugation stabilization of radicals but resonance can also stabilize
radicals. The difference between this answer and the correct answer is actually
only 3 hyperconjugation resonance forms versus resonance into the benzene ring
since a radical on the carbon alpha to the benzene ring will have 2
hyperconjugation resonance forms.
