I believe this question has the following five choices to choose from:
>an SN2 reaction has occurred with inversion of configuration
>racemization followed by an S N 2 attack
>an SN1 reaction has taken over resulting in inversion of configuration
>an SN1 reaction has occurred due to carbocation formation
>an SN1 reaction followed by an S N 2 “backside” attack
The correct answer is:
an SN1 reaction has occurred due to carbocation formation