<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 74-year-old man returns to his physician to follow-up on laboratory studies obtained for anemia 2 weeks ago. He has no complaints. He has a 20-year history of hypertension and several years of knee osteoarthritis. He walks 2 miles a day. He does not smoke. He drinks alcohol moderately. He takes hydrochlorothiazide, losartan, and pain killers, including ibuprofen. The vital signs include: temperature 37.1C 98.8F, pulse 68min, respiratory rate 12min, and blood pressure 11070 mm Hg. The physical examination shows no abnormalities. The laboratory studies show the following:Laboratory testHemoglobin 10 gdLMean corpuscular volume 75 μm3Leukocyte count 5,000mm3Platelet count 350,000mm3ESR 18 mmhrSerumFerritin 5 μgLIron 30 μgLTotal iron-binding capacity 500 μgdLCalcium Ca 9 mgdLAlbumin 4 gdLUrea nitrogen 14 mgdLCreatinine 0.9 mgdLMonoclonal protein on serum electrophoresis is 12 gL non-IgM. Clonal bone marrow plasma cells comprise 4 of the total number of cells. Skeletal survey with magnetic resonance imaging reveals no pathologic findings. In addition to iron deficiency anemia, which of the following diagnosis is most appropriate to consider?? A: Monoclonal gammopathy of undetermined significance, B: Smoldering asymptomatic multiple myeloma, C: Solitary plasmacytoma, D: Symptomatic multiple myeloma, E: Waldenstroms macroglobulinemia,  <response>: This is a clinical case about a 74-year-old man with anemia. Based on the information provided, the key findings are:- Anemia with low hemoglobin, low MCV, low ferritin and low iron indicating iron deficiency anemia.- Monoclonal protein detected on serum electrophoresis. - 4 clonal plasma cells in bone marrow.- No evidence of end organ damage such as hypercalcemia, renal insufficiency, anemia or bone lesions.This narrows the differential diagnosis to monoclonal gammopathy disorders. Monoclonal gammopathy of undetermined significance MGUS is the most likely diagnosis given the low tumor burden based on serum monoclonal protein level and percentage of clonal plasma cells. Solitary plasmacytoma and symptomatic multiple myeloma can be ruled out due to lack of findings localized to a single site or end organ damage. Waldenstroms macroglobulinemia is unlikely given the monoclonal protein is not IgM. Smoldering asymptomatic multiple myeloma is possible but MGUS is more likely given the very low tumor burden.A: Monoclonal gammopathy of undetermined significance 