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': 'All of the following drugs are primarily bacteriostatic except \nSelect and explain. \nA. Sulphonamide, B. Chloramphenicol, C. Ethambutol, D. Rifampicin', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]