Hepatobiliary Disease USMLE Step 1 Practice Question

A 57-year-old man is hospitalized in shock (BP 85/52, HR 128, RR 22) following massive traumatic blood loss requiring massive transfusion. Two days later, he remains hypotensive despite resuscitation. Laboratory studies reveal marked aminotransferase elevation (AST 3,240 U/L, ALT 2,890 U/L) with normal bilirubin. Abdominal ultrasound shows normal hepatic vasculature without thrombosis. Which region of the hepatic acinus is most vulnerable to this ischemic hepatic injury?