Answer:
A & C
Step-by-step explanation:
The VDJ regions of immunoglobulins change a lot due to somatic mutations of the genes that code for these regions in the B cells of the immune system This is called somatic hypermutation and occurs in the lymphoid tissues. Most of these mutations will be deleterious while some will increase the affinity of a target. These effective immunoglobulins will be reserved in memory B cells and improve immunity against the target in the next invasion.
Somatic recombination (akin to genetic recombination in meiosis) – such as chromosomal translocations- also add to this diverse repertoire of the immunoglobulins because they increase the genetic diversity of lymphocytes and the type of Ig s they produce.