The use of antibiotics can be based on either the clinical course of a patient without the benefit of well-defined microbiologic data (empiric therapy), or targeted at specific identified pathogens once sensitivity reports are available (directed therapy). The following statement(s) is/are true concerning these therapies. a. The issue of toxic side effects of antibiotics is only important in dealing with emperic therapy b. Single agent therapy is generally inferior to specific multi-drug therapy (aminoglycoside plus an antianaerobic agent) for the treatment of secondary bacterial peritonitis due to appendicitis, diverticulitis, penetrating gastrointestinal injury, or anastomotic leak c. With the empiric use of antibiotics, a diligent search for the septic source should be undertaken and continued until identified d. In clinical situations in which polymicrobial infection is identified, specifically-directed treatment for the predominant organism is satisfactory