Question

If the heterozygote codes for the average of a particular phenotype, and being average brings about a reproductive advantage, over time what would the phenotype distribution look like, and what type of selection would have occurred?
stabilizing selection with a homozygote genotype increasing
stabilizing selection with a heterozygote genotype increasing
disruptive selection with both homozygote genotypes increasing
disruptive selection with the heterozygote increasing
directional selection toward both homozygotes