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: Pharmacology
[{'content': 'Which of the following antitubercular drug is preferred in severe liver disease ? \nSelect and explain. \nA. Streptomycin + Isoniazid, B. Streptomycin + Ethambutol, C. Isoniazid + Rifampicin, D. Rifampicin + Ethambutol', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]