This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
Which is the earliest marker of hepatocellular failure ? 
Select and explain. 
A. Abnormal PTT, B. Decrease Albumin: Globulin ratio, C. Increased PT, D. Increased ammonia
C: Increased PT
Answer: C: Increased PT 
Explanation: The PT and/or the international normalized ratio (INR) are used to determine the presence or severity of coagulopathy. They are earliest and sensitive markers of hepatic synthetic failure. The serum ammonia level may be elevated dramatically in patients with fulminant hepatic failure. The aerial serum ammonia level is most accurate, but venous ammonia levels are generally acceptable. An elevated serum ammonia level does not exclude the possibility of another cause for mental status changes. Albumin:globulin ratio commonly decreases in hepatic failure.