1. A 62-year-old m an presented to his physician com plaining of tiredness and abdom inal pain. Medical history revealed that the m an had been taking two tablets of naproxen tw ice daily for...

1. A 62-year-old m an presented to his physician com plaining of tiredness and abdom inal pain. Medical history revealed that the m an had been taking two tablets of naproxen tw ice daily for arthritic pain for the past 3 m onths. Pertinent lab results on adm ission were red blood cell count (RBC) 3.1 × 106/mm3 (norm al, m ale 4.3-5.9 × 106/mm3), hem oglobin 8.5 g/dL (norm al, m ale > 13.5 g/dL), m ean corpuscular volum e 70 fL (norm al 80-100 fL), serum ferritin 6 ng/m L (norm al: 30-300). An appropriate therapy was prescribed. Which of the follow ing actions m ost likely m ediated the therapeutic e ect of the prescribed drug? A. Activation of speci c receptors on RBC progenitors B. Replacem ent of a chem ical w hose stores are severely depleted C. Increased life span of RBCs D. Stim ulation of erythropoietin production by the kidney E. Stim ulation of transferrin production by the liver