Which Event Does Not Occur During Formation of the Heavy

Which event does not occur during formation of the heavy chain of an antibody?

A) Assembly of supergenes by splicing of individual genes of the heavy chains is coordinated with that of light chains.
B) Before transcription, a variable region supergene is formed through DNA rearrangement in which one each of the variable genes (V) , diversity genes (D) , and joining genes (J) are joined together.
C) Following RNA splicing, mRNA is translated to produce a polypeptide chain.
D) After transcription, RNA splicing removes introns and joins the variable region to the constant region.
E) Mutations occur due to imprecise recombination of selected DNA regions.