Baldness is more common in men than in women. It could be explained on the basis that

The correct option is A Genes of baldness are located on X-chromosomes only
Male baldness is a sex-linked recessive trait. Genes for baldness are located on the X chromosome. Females require two sets of defective gene to express baldness. Whereas males require only one set of defective gene to express baldness as males have only one set of X chromosome.

Thus, the correct answer is 'Genes of baldness are located on X-chromosomes only'.