M. B. is a generally healthy 36-year-old woman with complaints of persistent generalized fatigue. At her annual checkup she is noted to have the following vital signs: heart rate 118 beats/min, blood pressure 128/60, oral temperature 37o C, and respiratory rate 26 breaths/min. Her skin and nail beds are pale. Laboratory results demonstrate hematocrit (Hct) 31%; hemoglobin (Hb) 10 g/dl; mean corpuscular hemoglobin concentration 27; mean corpuscular volume 70; total iron binding capacity 600 mg/dl. What other history data would be helpful in determining the cause of this disorder? A. Heavy menses or other source of chronic bleeding. B. Joint pain. C. Pale conjunctiva. D. Abdominal pain.