Final answer:
The correct term for the process where rearranged VDJ genes in a memory B cell are associated with different constant region genes to produce various classes of antibodies while maintaining antigen specificity is isotype switching.
Step-by-step explanation:
The process by which rearranged VDJ genes within a memory B cell become juxtaposed with different C region genes is known as isotype switching. This is a mechanism that allows a B cell to produce different classes of antibody (IgM, IgG, IgA, etc.) while maintaining specificity for the antigen that the cell recognizes. This switch occurs after DNA recombinase randomly excises V and J segments from the light chain gene and splices them, generating a myriad of VJ combinations that contribute to the unique variable region of each antibody capable of binding different antigens. The constant domain of these antibodies, which does not bind antigens, remains the same across all antibodies of a specific class. Therefore, the correct response from your list would be c) Isotype switching.