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
All are biomarkers of long standing alcohol intake, EXCEPT: 
Select and explain. 
A. Carbohydrate deficient transferrin, B. GGT, C. 5' nucleotidase, D. Macrocytosis
C: 5' nucleotidase
Answer: C: 5' nucleotidase 
Explanation: GGT will be elevated in long standing alcoholism, but it lack sensitivity and specificity. Elevated MCV seen in chronic alcoholism. CDT is most widely studied but it lack sensitivity and specificity. 5' nucleotidase is an cholestatic marker. Ref : AASLD Practice Guidelines 2010