, to determine the genotype of a hybrid (F1) or any organism showing a dominant phenotype, a test cross is performed. In a typical test cross, the organism is crossed with the recessive parent (double recessive genotype). While the correct scientific definition specifies the 'recessive parent', among the given options, crossing the F1 progeny with a parent (Back Cross) is the methodology described. If the male parent represents the recessive trait in the specific experimental context (or if the option implies a test cross), this allows the analysis of offspring phenotypes to determine the unknown genotype.