In familial hypercholesterolemia, individuals homozygous for the allele causing the disorder completely lack receptors on liver cells that take up cholesterol from the blood stream. Heterozygotes have one-half the number of receptors while individuals homozygous for the normal allele are phenotypically normal. This is the example of what?A. Complete dominance. B. Co-dominance. C. Incomplete dominance. D. Epistasis.