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
Dubin Johnson syndrome characteristically makes the liver: 
Select and explain. 
A. Black, B. Blue, C. Red, D. White
A: Black
Answer: A: Black 
Explanation: This rare autosomal recessive condition, characterized by conjugated hyperbilirubinemia, with normal liver transaminases, a unique pattern of urinary excretion of heme metabolites (coproporphyrin) and the deposition of a pigment, that gives liver a characteristic black color.