<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 55-year-old male presents with complaints of intermittent facial flushing. He also reports feeling itchy after showering. On review of systems, the patient says he has been having new onset headaches recently. On physical exam, his vital signs, including O2 saturation, are normal. He has an abnormal abdominal mass palpable in the left upper quadrant. A complete blood count reveals: WBCs 6500microliter; Hgb 18.2 gdL; Platelets 385,000microliter. Which of the following is most likely responsible for his presentation?? A: Elevated serum erythropoietin levels, B: Fibrosis of bone marrow, C: Tyrosine kinase mutation, D: BCR-ABL fusion, E: Chronic hypoxemia,  <response>: Based on the patients symptoms of facial flushing, itchy skin after showering, and new onset headaches, as well as the abnormal blood count showing elevated hemoglobin and platelets, this presentation is most consistent with a myeloproliferative neoplasm. The specific findings of an elevated hemoglobin and platelets point towards polycythemia vera as the likely diagnosis. The abnormal abdominal mass could represent splenomegaly which can be seen in myeloproliferative neoplasms. Of the answer choices, a tyrosine kinase mutation leading to uncontrolled proliferation of myeloid lineage cells is the most likely underlying cause. Elevated erythropoietin, bone marrow fibrosis, and BCR-ABL fusion protein would not explain this presentation. Chronic hypoxemia would not lead to polycythemia with high hemoglobin and platelets.C: Tyrosine kinase mutation 