In the absence of chromosomal abnormalities, all humans in any given time typically have homologous chromosomes with ___.

a Only one allele representing a gene that occupies the same locus b Only two alleles representing a gene that occupies the same locus c Only one allele representing a gene that occupies multiple loci d Only two alleles representing a gene that occupies multiple loci e Only three alleles representing a gene that occupies the same locus