A 29-year-old woman was found to have a hemoglobin of 7.8 g/dl. With a reticulocyte count of 0.8%. The peripheral blood smear showed microcytic, hypochromic anemia. Hemoglobin A2 and hemoglobin F leves were 2.4% and 1.3% respectively. The serum iron ug/dL and 420 ug/dL respectively. The most likely cause of anemia is:
1. Iron deficiency anemia.
2. B-thallessemia minor.
3. Sideroblastic anemia.
4. anemia due to chronic infection.