Which of the following bromides has no beta-hydrogen and therefore cannot undergo a direct one-step E2 dehydrohalogenation (without rearrangement)?

E2 needs a hydrogen on a carbon adjacent to the carbon bearing the halogen. In neopentyl bromide the adjacent carbon is quaternary and carries no hydrogen. The other three bromides all have beta hydrogens, for instance the methyl hydrogens of tert-butyl bromide.