The mechanism of the following reaction is
A. SN1.
B. SN2.
C. E1.
D. E2.
Solution: SN are nucleophilic substitution reactions where the leaving group is replaced by the nucleophile. E are elimination reactions that create a double bond. The products have no double bond and we can eliminate choices C and D. SN2 prefers primary substrate while SN1 prefers tertiary. Here the substrate is methyl. Therefore, SN2 would be the reaction here. Choice B