This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Pathology
[{'content': 'The genetic defect in Dubin-Johnson Syndrome is \nSelect and explain. \nA. Mutation in gene for multiple drug resistance protein 2, B. Mutation in gene UDP- glucuronyl transferase, C. Mutation of chromosome 23, D. Flash mutations', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Dubin-Johnson syndrome is a rare, autosomal recessive, benign disorder that causes an isolated increase of conjugated bilirubin in the serum. Classically, the condition causes a black liver due to the deposition of a pigment similar to melanin. Refer robbins 9/e', 'role': 'assistant'}]