<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 24-year-old woman complains of intermittent fever and joint pain. She says that these symptoms have been present for the past month. Before that, she had no signs or symptoms and was completely healthy. She has also lost her appetite and some weight. A complete blood count CBC showed severe pancytopenia. What is the next best step in evaluating this patient?? A: Bone marrow examination, B: Treatment with antibiotics, C: Repeated CBCs for several weeks and reassess, D: Treatment with corticosteroids, E: Treatment for acute leukemia,  <response>: This appears to be a case of a previously healthy 24-year-old woman who has developed intermittent fever, joint pain, loss of appetite, weight loss, and pancytopenia over the past month. The acute onset of these nonspecific symptoms along with pancytopenia is concerning for a bone marrow process such as leukemia, aplastic anemia, or myelodysplastic syndrome. The next best step would be to directly evaluate the bone marrow to look for evidence of one of these diseases. Repeated CBCs may show worsening pancytopenia but does not provide additional diagnostic information. Empiric antibiotics, steroids, or leukemia treatment would be premature without a definitive diagnosis from bone marrow examination.A: Bone marrow examination 