The correct option is A Phenocopy
When two genotypes produce the same phenotype due to different environments, then each one is called the phenocopy of the other, because they differ genotypically, e.g., in Drosophila, the normal body colour is brown and a hereditary variant has a yellow colour, when the larvae of wild type Drosophila with brown body colour are raised on food containing silver salts, they develop into yellow bodied flies. Thus, these flies are the phenocopies of yellow mutant, but would give rise to wild type brown flies in normal environment.