S_N2 Reactions Usually Proceed with ________

S_N2 reactions usually proceed with ________.

A) equal amounts of inversion and retention at the asymmetric center undergoing substitution
B) slightly more inversion than retention at the asymmetric center undergoing substitution
C) slightly more retention than inversion at the asymmetric center undergoing substitution
D) complete inversion at the asymmetric center undergoing substitution
E) complete retention at the asymmetric center undergoing substitution