Gross Anatomy USMLE Step 1 Practice Question

A 68-year-old man with a 50-pack-year smoking history, hypertension, and hyperlipidemia presents to the emergency department with acute lower abdominal and pelvic pain. On examination, he has a pulsatile abdominal mass and diminished femoral pulses bilaterally. CT angiography demonstrates a ruptured abdominal aortic aneurysm with extension into the iliac bifurcation. During emergency repair, the vascular surgeon must ligate the bilateral internal iliac arteries to control hemorrhage. Which of the following organs would be most at risk for ischemic injury due to loss of its primary arterial supply?