In an SN1 reaction on chiral centers, there is:

In an SN1 reaction on chiral centers, there is inversion more than retention leading to initial racemization. Thus if we start with a pure enantiomer and carry out SN1 substitution on chiral carbon, the product will be racemic. This is because a planar carbocation intermediate is obtained. The nucleophile can attack from either side of this intermediate. Option D is correct.