Answer:
(b) 2-chloro-3,3-dimethylpentane
Explanation:
A rearrangement occurs in a SN1 reaction when the carbocation is formed. More substituted carbocations are more stable because of the electron-donating effect of alkyl groups and the hyperconjugation.
An alkyl halide with a carbon more substituted than the carbon where is the C-X bond, is most likely to undergo rearrangement.
(a) 1-bromo-4-methylcyclohexane
In this molecule could occur a rearrangement but the carbocation need to jump three bonds.
(b) 2-chloro-3,3-dimethylpentane
This alkyl halide is most likely to occur a rearrangement because the near carbon is a quaternary carbon.
(c) 3-bromopentane
Can't occur a rearrangement because all carbons are secondary
(d) bromocyclohexane
Also, can't occur a rearrangement because all carbons are secondary.
Thus, the most likely to undergo rearrangement in an SN1 reaction is (b) 2-chloro-3,3-dimethylpentane
I hope it helps!
