You are answering a USMLE-style medical question. Question: A 36-year-old man is brought to the emergency department 25 minutes after being involved in a high speed motor-vehicle collision in which he was an unrestrained passenger. He has acute myeloid leukemia and is currently receiving chemotherapy. On arrival, his temperature is 37°C (98.6°F), pulse is 63/min, respirations are 10/min, and blood pressure is 100/70 mm Hg. The pupils are equal and sluggish. There are multiple bruises over the face, trunk, and right upper and lower extremities. There is a 4-cm (1.6-in) laceration over his right cheek. He does not respond to any commands, but does groan. Painful stimuli cause him to open his eyes and withdraw all extremities. There are decreased breath sounds over the right lung base. There is tenderness to palpation over the left chest wall. Cardiac examination shows no abnormalities. The abdomen is soft and shows diffuse tenderness to palpation with no guarding or rebound. There is swelling of the right elbow and wrist. The right lower extremity is shorter than the left lower extremity. There are 2 lacerations around 2 cm (0.8 in) each on the right leg. The right knee is swollen. Which of the following is the most appropriate next step in management? Options: A) Insertion of intercostal chest tube B) CT scan of the head and neck C) X-rays of the extremities D) Intubation and mechanical ventilation Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.