Final answer:
SHM, or Somatic Hypermutation, is a biological process that increases the binding efficiency of antibodies to antigens by mutating the immunoglobulin genes. It augments the specificity and efficacy of the adaptive immune response by enhancing the affinity of antibodies for their corresponding antigens.
Step-by-step explanation:
The function of SHM (Somatic Hypermutation) is best described by increasing the affinity of immunoglobulins for their antigen. This process involves the mutation of the variable regions of immunoglobulin genes, especially after antigen exposure, to improve the binding efficiency of antibodies to specific antigens. SHM occurs in mature B cells in the germinal centers of lymphoid organs.
During B cell maturation, antibody diversification occurs through recombination and mutation of gene segments V (Variable), D (Diversity), and J (Joining) linked to a C (Constant) region to create a unique V-D-J-C structure for each antibody. This provides the initial variety of antigen-binding specificities. However, after antigen exposure, SHM takes place, which further fine-tunes the antibody's ability to bind more tightly to its specific antigen, thus enhancing its specificity and efficacy.
Therefore, the answer to the question is B. Increasing the affinity of immunoglobulins for their antigen.