This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hepatitis, Subject name: Medicine
Severity in acute hepatitis is best estimated by: 
Select and explain. 
A. Serum bilirubin, B. Prothrombin time, C. a-glutaryl transferase, D. Alkaline phosphatase
B: Prothrombin time
Answer: B: Prothrombin time 
Explanation: Laboratory findings in Acute Hepatitis WBC count normal to low (pre icteric phase) Large atypical lymphocytes Mild proteinuria Bilirubinuria AST, ALT strikingly elevated Elevated Bilirubin and alkaline phosphatase Marked prolongation of prothrombin time.