<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 45-year-old man presents to the emergency department with fever and easy bruising for 3 days. He has had fatigue for 2 weeks. He has no past medical history, and takes no medications. Excessive bleeding from intravenous lines was reported by the nurse. He does not smoke or drink alcohol. The temperature is 38.2C 102.6F, pulse is 105min, respiration rate is 18min, and blood pressure is 11070 mm Hg. On physical examination, he has multiple purpura on the lower extremities and several ecchymoses on the lower back and buttocks. Petechiae are noticed on the soft palate. Cervical painless lymphadenopathy is detected on both sides. The examination of the lungs, heart, and abdomen shows no other abnormalities. The laboratory test results are as follows:Hemoglobin 8 gdLMean corpuscular volume 90 μm3Leukocyte count 18,000mm3Platelet count 10,000mm3Partial thromboplastin time activated 60 secondsProthrombin time 25 seconds INR: 2.2Fibrin split products PositiveLactate dehydrogenase, serum 1,000 ULA Giemsa-stained peripheral blood smear is shown by the image. Intravenous fluids, blood products, and antibiotics are given to the patient. Based on the most likely diagnosis, which of the following is the best therapy for this patient at this time?? A: All-trans retinoic acid ATRA, B: Citarubin plus daunorubicin, C: Hematopoietic cell transplantation, D: Rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone R-CHOP, E: Adriamycin, bleomycin, vinblastine, and dacarbazine ABVD,  <response>: This is a question about a 45-year-old man with fever, easy bruising, fatigue, purpura, ecchymoses, and lymphadenopathy. The key lab findings are thrombocytopenia, prolonged PTPTT, elevated LDH, and leukoerythroblastic blood smear. The clinical presentation and lab findings are most consistent with acute promyelocytic leukemia APL. APL is characterized by pancytopenia, DIC, and the pathognomonic finding of hypergranular promyelocytes on peripheral smear. The choices given are various chemotherapy regimens. The best initial therapy for APL is ATRA all-trans retinoic acid, which induces differentiation of the leukemic promyelocytes. ATRA plus anthracycline-based chemotherapy leads to high cure rates for APL.A: All-trans retinoic acid ATRA 