Final answer:
Isotype switching, or class switching, in antibody production allows plasma cells to produce different classes of antibodies with the same specificity. An example of isotype switching is the change from IgG to IgE.
Step-by-step explanation:
Isotype switching, also known as class switching, is a mechanism in antibody production where plasma cells change the class of antibody they produce. This process allows plasma cells to produce different antibody classes with the same specificity for an antigen. An example of isotype switching is the change from IgM to IgG, IgA or IgE. Therefore, the correct answer is b) IgG to IgE.