In Germinal Centers, Proliferating B Cells Undergo a Process Called

In germinal centers, proliferating B cells undergo a process called somatic hypermutation, in which mutations are introduced into the V regions of the antibody heavy and light chain genes. When this process is complete after several weeks, the overall affinities of the antibodies produced are greatly increased compared to those present early in the primary response. The somatic hypermutation process leads to increased antibody affinity because:

A) Mutations that decrease the antibody affinity lead to an arrest of B cell proliferation.
B) B cells making higher affinity antibodies receive more help from T_FH cells.
C) Somatic hypermutations only take place in the sequences encoding the CDR1, CDR2, and CDR3 regions.
D) Mutations that increase antibody affinity lead to an increased rate of B cell proliferation.
E) The majority of nucleotide changes introduced by AID don't change the amino acid coding sequence.