<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:Three days into hospitalization for a fractured distal femur, a 33-year-old man develops dyspnea and confusion. He has no history of a serious illness. He is unable to answer any questions or follow any commands. His blood pressure is 14590 mm Hg, the pulse is 120min, the respiratory rate is 36min, and the temperature is 36.7C 98.1F. His oxygen saturation is 90 on 80 FiO2. On examination, purpura is noted on the anterior chest, head, and neck. Inspiratory crackles are heard in both lung fields. Arterial blood gas analysis on 80 FiO2 shows:pH 7.54PCO2 17 mm HgPO2 60 mm HgHCO3 22 mEqLA chest X-ray is shown. Which of the following best explains the cause of these findings?? A: Acute respiratory distress syndrome, B: Fat embolism, C: Hospital-acquired pneumonia, D: Pulmonary contusion, E: Pulmonary thromboembolism,  <response>: This is a clinical vignette describing a 33-year-old man with a recent femur fracture who develops acute respiratory distress 3 days after hospitalization. Key findings include dyspnea, confusion, purpura, hypoxemia, and diffuse pulmonary infiltrates on chest X-ray. The hypoxemia and respiratory alkalosis on ABG indicate acute lung injury. The purpura and temporal relationship to the femur fracture point towards fat embolism syndrome. The chest X-ray shows diffuse bilateral infiltrates consistent with acute lung injury, rather than a focal consolidation that would be expected with pneumonia or contusion. There is no evidence to suggest thromboembolism.Therefore, the cause that best explains his presentation is fat embolism syndrome, a known complication of long bone fractures that can occur 2-5 days after injury. Fat droplets are released into the venous circulation and travel to the lungs causing respiratory distress. B: Fat embolism 