The correct option is C chemical method
Enzymes are stereospecific chiral protein molecules that act as catalysts. Because of their chirality, these molecules react with only one enantiomer in a racemic mixture. The enantiomer that momentarily bonds to an enzyme undergoes reaction, while the enantiomer that does not bond remains unchanged.
The unreacted enantiomer can then be removed from the reaction mix by ordinary separation methods, such as distillation or recrystallization.