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: Biochemistry
What is the gold standard investigation for Wilson's disease? 
Select and explain. 
A. Measurement of serum ceruloplasmin, B. 24 hour urinary copper excretion, C. Liver biopsy, D. Serum copper estimation
C: Liver biopsy
Answer: C: Liver biopsy 
Explanation: Gold standard investigation for Wilson's disease is liver biopsy with quantitative copper assay.