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: 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 UDP-glucuronyl transferase, C. Mutation of chromosome 23, D. Flash mutations', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]