RBC count is less in females as compared to males due to?

ANSWER: (B) Blood loss during menstruationREF: With text "In prepubertal humans no major differences can be found between the sexes in RBC count and hemoglobin or serum ferritin concentrations. Only after the onset of menstruation does a difference emerges due to loss of blood in menstruation" (REF: BM J: British medical journal:Volume 322, Issues 7295-7302 page 1355)After puberty, values for the hematocrit, blood hemoglobin concentration, and red cell count average approximately 10 to 13% higher in men than in women. In castrated men, these values fall to within the normal female range. This is almost certainly due to a difference in erythropoietin production, although the relationship between hemoglobin and erythropoietin concentration does not differ between the sexes. After the sixth decade, male hemoglobin values fall back toward those observed in women. The anemia in these patients is corrected by androgen replacement. The differences in red cell parameters between the sexes are accounted for chiefly by the stimulating effect of androgens on erythropoiesis. In addition, some observers suggest that estrogens exert a suppressive effect. (REF: Wintrobe's Clinical Hematology, 11th Ed chapter 47)