Read the following statements and select the one that is incorrect.
Statement A: ABO blood grouping is an example of a trait controlled by multiple alleles, specifically three alleles.
Statement B: In peas, the B allele is completely dominant over the b allele for the trait of seed shape.
Statement C: Heterozygotes for the B and b alleles in peas produce seeds with starch grains of intermediate size, demonstrating incomplete dominance for starch grain size.
Statement D: Every individual can exhibit traits governed by all alleles available in a population.