<prompt> Answer this question truthfullyAmong the immunoglobulins, which one has the highest affinity for antigens?  <response>: <reason> The immunoglobulin that has the highest affinity for antigens is IgG. Affinity refers to the strength of binding between an antibody and a single epitope on an antigen. IgG is a monomeric antibody that has two antigen-binding sites, which allows it to bind tightly to a specific antigen. This results in a high-affinity binding, which is important for the effective clearance of pathogens. In contrast, IgM antibodies have a higher avidity because they have multiple antigen-binding sites, which allows them to bind to multiple epitopes on an antigen simultaneously. Both high-affinity binding and high-avidity binding are important for the effectiveness of the immune response. 