A monoclonal antibody, specific for a virus, was treated with an enzyme to break the bonds between the variable and constant regions. The separated variable and constant regions were then added to cells infected with the virus. Which statements are correct? 1 The constant regions would bind to different parts of the virus antigens. 2 The viruses could be engulfed by phagocytes if they were present. 3 The variable regions would all bind to the same part of the virus antigens.