Which nucleophilic substitution reaction will proceed?

Question

Quizplus · Accepted Answer

In reaction II, the leaving group (Br) is attached to a tertiary carbon, making it the most reactive towards nucleophilic substitution. In reaction I, the leaving group is attached to a primary carbon, which makes it the least reactive. In reaction III, the leaving group is attached to a secondary carbon, which is moderately reactive. In reaction IV, the solvent is not polar enough and the leaving group is not attached to a good electrophile, so the reaction will not proceed. Therefore, the best choice is reaction II.

Which Nucleophilic Substitution Reaction Will Proceed