<prompt> Which of the following immunoglobulins has the highest mean serum concentration in humans?IgAIgDIgGIgM  <response>: IgG is the most abundant class of immunoglobulins in the serum, comprising about 80 of the total serum immunoglobulin.There are four IgG subclasses IgG1, IgG2, IgG3, and IgG4so numbered according to their decreasing concentrations in serum.Parija SC. Textbook of Microbiology Immunology. Elsevier Health Sciences; 2014. Page:96 