Modern Cloning Techniques Have Demonstrated That the Vast Majority of Differentiated

Modern cloning techniques have demonstrated that the vast majority of differentiated cells are genetically equivalent to developing cells in the embryo.What example below is an exception to this finding?

A) Nerve cells are often limited in their mitotic activity.
B) In the immune system,sequences of DNA may rearrange to permit response to new pathogens.
C) In the brain,DNA sequences may change with learned behavior.
D) The lining of the digestive system is frequently replaced.Some of these cells may show repeats of certain DNA sequences.