Answer:
The correct option is A. The organic substrate is (S) and the organic product is (R).
Explanation:
The correct answer is A because in stereochemistry we denote the substrate as S and the product of the reaction is denoted by R. Hence, A is the correct option. The mechanism of the reaction of SN2 reaction can be described as: It is a one-step nucleophilic substitution reaction. It is known as the SN2 reaction because two reactants are involved in the rate-determining step. The mechanism of reaction involves the attack of the nucleophile on the electrophile which results in a transition phase with the alkyl group leaving the electrophile and the nucleophile forming a new bond with the remaining substrate.