Which one of the following factors proceeds more rapidly, unimolecular nucleophilic substitution reaction?

Step-by-step solution

Unimolecular nucleophilic substitution ( S_ N 1 ) reactions proceed via the formation of a carbocation intermediate in the rate-determining step. Polar protic solvents have high dielectric constants and are capable of hydrogen bonding. They stabilize both the carbocation intermediate and the leaving group anion through solvation. This stabilization lowers the activation energy required for the cleavage of the carbon-halogen bond, thereby increasing the rate of the S_ N 1 reaction. The strength of the nucleophile do