With Respect to X-Chromosome Inactivation, Which, If Any, of the Following

Multiple Choice

With respect to X-chromosome inactivation, which, if any, of the following statements are not correct ?

A) X-chromosome inactivation in mammals begins in the pre-implantation embryo
B) In humans all diploid cells that carry two normal X-chromosomes are subject to a random pattern of X-inactivation.
C) Once a decision has been made to inactivate an X chromosome (either the paternal or maternal X) , all descendant cells show the same pattern of X-inactivation.
D) The inactivated X chromosome becomes a highly condensed Barr body in which genes are silenced across the length of the chromosome.