This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Liver disorders, Subject name: Pediatrics
[{'content': 'In a child with acute liver failure, the most impoant abnormal serum biochemical test that indicates poor prognosis: \nSelect and explain. \nA. Increasing transaminases, B. Increasing bilirubin, C. Increasing prothrombin time, D. Reversal of serum albumin-globulin ratio', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Definition of Acute liver failure in children includes: Biochemical evidence of acute liver injury (usually <8 wk duration); No evidence of chronic liver disease; Hepatic-based coagulopathy defined as i) a prothrombin time (PT) >15 sec or international normalized ratio (INR) >1.5 not corrected by vitamin K in the presence of clinical hepatic encephalopathy, or ii) a PT >20 sec or INR >2 regardless of the presence of clinical hepatic encephalopathy. Hepatic synthetic function is reflected in serum albumin and protein levels and in the PT or INR Unresponsiveness of PT to vitamin K suggests severe hepatic disease Serum aminotransferase activities do not correlate well with the severity of the illness.', 'role': 'assistant'}]