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 one of the following drugs is not used in the treatment of mycobacterium avium intercellulare infection ? \nSelect and explain. \nA. Clarithromycin, B. Eflornithine, C. Ethambutol, D. Rifabutin', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]