If the nucleotide variability of a locus equals 0%, what is the gene variability and number of alleles at that locus? (A) gene variability = 0%; number of alleles = 0 (B) gene variability = 0%; number of alleles = 1 (C) gene variability = 0%; number of alleles = 2 (D) gene variability > 0%; number of alleles = 2