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': 'MDR tuberculosis is defined by : \nSelect and explain. \nA. Resistance to all first and second line anti-tubercular agents, B. Resistance to any three first line anti-tubercular agents, C. Resistance to all first line and any three classes of second line anti-tubercular agents, D. Resistance to isoniazid and rifampicin', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]