The chromosomes can be distinguished into autosomes and allosomes. Autosomes are somatic chromosomes carrying the genes which determine the somatic characteristics and do not have any influence on determining the sex of the organism. Allosomes are sex chromosomes which carry genes responsible for sexual characteristics and as such have a significant role in the determination of sex. Generally, one specific pair of chromosomes in the diploid number is identified as the allosomes. While the two members of each pair of autosomes are identical morphologically and genetically, it may not be the same for allosomes, particularly in males. Thus, option B is correct and other options are wrong.