Women Known to Be Heterozygous or Carriers for the Sex-Linked

Women known to be heterozygous or carriers for the sex-linked recessive condition of hemophilia A were studied to determine the time required for their blood to clot. It was found that the time required for their blood to clot varied from individual to individual. The values obtained ranged from normal clotting at one extreme to clinical hemophilia at the other extreme. What is the MOST probable correct explanation for these findings?

A) Some women had only one X chromosome and it is inactive.
B) Some women had three copies of the X chromosome, which allowed them to make extra amounts of gene products for their X-linked genes.
C) The women with normal clotting times probably had a mother with hemophilia while those with abnormal clotting times probably had fathers with hemophilia.
D) Random X inactivation probably results in individuals with different proportions of cells in their bodies expressing the normal allele at the hemophilia locus.
E) In women with abnormal clotting times, there was probably an interaction between an allele of a gene on the X chromosome and an allele of an autosomal gene that reduced the expression of the X-linked gene.