A 6-year-old child ate a peanut butter sandwich at snack time in school. five minutes later, her throat became swollen and she collapsed. this allergic reaction occurred because her body (1) recognized an antigen in peanut butter and produced antibiotics against it (2) digested the white blood cells that can recognize an antigen in peanut butter (3) did not recognize an antigen in peanut butter and could not produce antibodies against it (4) recognized an antigen in peanut butter and produced an immune response