Concept:Dominant and recessive characters are determined by alleles occupying corresponding positions on homologous chromosomes.Explanation:Alleles are different forms of the same gene.They are located at the same position, called the locus, on each of a pair of homologous chromosomes.Therefore, a dominant allele and its recessive counterpart are found at the same locus on homologous chromosomes.Answer:B. at the same locus of a homologous chromosome