This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Trauma, Subject name: Surgery
A 60-year-old man is hit by a pickup truck and brought to the emergency department with a blood pressure of 70/0 mm Hg. Peritoneal lavage showed no blood in the abdomen. The blood pressure is elevated to 85 systolic following the administration of 2 L of Ringer's lactate. An x-ray showed a pelvic fracture. What is the next step in management? 
Select and explain. 
A. Exploratory laparotomy with packing of the pelvis, B. CT scan of the pelvis, C. External fixation of the pelvis, D. Open reduction and internal fixation (ORIF) of the pelvis
C: External fixation of the pelvis
Answer: C: External fixation of the pelvis 
Explanation: Early external fixation of the pelvis has been shown to reduce bleeding and mortality in patients in shock consequent to pelvic fractures. An unstable patient should not be sent for a CT scan. Selective angiography with embolization of the bleeding vessel may also be helpful in these patients. Laparotomy usually results in uncontrollable pelvic bleeding.