Which of the following statements regarding antibody molecules is correct? an antibody molecule is composed of four polypeptide chains and is shaped somewhat like a fork. the "tines of the fork" (fab ends of the molecule) combine with the antigen. the "handle of the fork" (fc end of the molecule) determines the properties of the molecule, such as the ability to activate complement. all antibodies are secreted as groups (clusters) of five individual antibody molecules that are joined together to form large molecules called macroglobulins.