In SN1 and SN2 reactions:
(A). SN1 is a unimolecular reaction with first-order kinetics, while SN2 is a bimolecular reaction with second-order kinetics.
(B). In SN2, the reaction proceeds through the formation of a carbocation, while SN1 does not.
(C). SN2 is a stereospecific reaction. The product forms with inversion of configuration only.
(D). SN1 reaction is favored in the presence of a weak base or poor nucleophile.
Choose the correct answer from the options given below: