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: Pediatrics
A 2 month baby presents with history of jaundice, turmeric colored urine and pale stools since birth. Examination reveals liver span of 10 cms. The most specific investigation for establishing the diagnosis would be – 
Select and explain. 
A. Liver function tests, B. Ultrasound abdomen, C. Peroperative cholangiogram, D. Liver biopsy
D: Liver biopsy
Answer: D: Liver biopsy 
Explanation: The given clinical picture is suggestive of either of the following diagnosis:

Neonatal hepatiits
Extra hepatic biliary atresia

"Percutaneous liver biopsy is the most valuable procedure in the evaluation of neonatal hepatobiliary disease and provides the most reliable discriminatory evidence".
Biopsy findings of biliary atresia

Bile ductular proliferation                        
Portal or perilobular edema and fibrosis.
Bile plug               
Intact basic hepatic lobular architecture.

Biopsy findings of Neonatal hepatitis

Severe, diffuse hepatocellular disease
Focal hepatocellular necrosis.
No alteration in bile ductules.
Distortion of lobular architecture.
Marked infiltration with inflammatory cells.

Giant cells are seen in both.