The correct answer is the directional selection.
Directional selection in population genetics refers to a method of natural selection in which an extreme phenotype is preferred over other phenotypes, making the allele frequency to curve with time towards the direction of that phenotype.
Under directional selection, the beneficial allele enhances as an outcome of the distinctions in the reproduction and survival between the different phenotypes. The upsurges are not dependent upon the dominance of the allele, and even if the allele is recessive, it will ultimately become fixed.
