الدموية

Mr. Miranda ,a 50 year old male is feeling weak for the past year or so, he gets tired early and has lost a lot of his humor, he is also finding it difficult to remember things, he is jobless and is living on social security benefits, he denies smoking or alcohol use but admits being charged with driving under intoxication three times ,his father and mother died of old age, he shares his room with four of his friends .his vitals are normal but there is pallor on examination ,CBC is ordered and the results are:
WBC 5,500mm3
Hemoglobin 7mg/dL
Hematocrit 24%
Platelets 196.000mm3
RBC count 1.7 million
MCV 119
MCH 36
MCHC 28%
Reticulocyte count 0.4 %
Peripheral smear showsd anisocytosis, poikilocytosis and basophilic stippling, what is the next step?
1) Iron studies.
2) Osmotic fragility test.
3) Serum B12 and folate levels.
4) Sugar water test.
5) bone marrow biopsy with Prussian blue staining.
6) Blood lead levels.