<prompt> After binding of complement and antibody on the surface of encapsulated bacteria, the process of phagocytosis by polymorphonuclear leukocytesmacrophages is enhanced by all of the following opsonins, except?C3b complement proteinIgG antibodyMannose binding lectin MBLCD11bCD18  <response>: The efficiency of phagocytosis is greatly enhanced when microbes are coated with opsonins for which the phagocytes express high-affinity receptors. The major opsonins are immunoglobulin G IgG antibodies, the C3b breakdown product of complement, and ceain plasma lectins, notably mannose-binding lectin and collectins, all of which are recognized by specific receptors on leukocytes. CD11bCD18 MAC-1 is macrophage integrin which help in binding of microbes to macrophages, and are not opsonins. 