Which of the following is an example of an epigenetic change in eukaryotes? A) a loss of an AT base pair from a gene B) the addition of methyl groups to cytosines in the promoter region of a gene C) the substitution of an AT base pair by a GC base pair in a gene as a result of a mistake during DNA replicationD) a deletion that simultaneously removes two genes from the genome E) None of these examples represents epigenetic changes.