Which of the following statements is correct about Retention / inversion of configuration during the course of a reaction? (a)Configuration is retained if reagent attacks from the same side of leaving group. (b)Configuration is inverted if reagent attacks from the backside of leaving group.

The configuration is retained because of the attack from the same side of the leaving group and if the leaving group attack from the back-side then the configuration is inverted. And if there is no cleavage of bond in the asymmetric center then there will be no change in the configuration. Hence, the correct answer is an option (d)