A and E are incorrect because the correct idiom is "unlike x, y".
Also A, C and E are in passive voice, active voice is preferred on GMAT.
Between D and B, B is shorter and more precise.
And that's what I wanted to discuss.
Look at option B from this angleMany people
, willing to believe that German shepherds and Doberman pinchers might be fully domesticated, are unwilling to believe the same of pit bulls.
--drop the modifier and search for antecedent for pronoun "same" and you wont find it.
don't you think this error is more critical that the wordiness in option D?