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 anti-TB drug requires acidic medium for action? \nSelect and explain. \nA. Isoniazid, B. Rifampicin, C. Pyrazinamide, D. Ethambutol', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Pyrazinamide requires acidic medium for action and active only against intracellular mycobacteria.', 'role': 'assistant'}]