This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Anatomy
[{'content': 'Multi drug resistant T.B is defined as resistance to \nSelect and explain. \nA. INH and pyrizinamide, B. INH and Rifampicin, C. Rifampicin and Pyrizinamide, D. Resistance to all first line of drugs', 'role': 'user'}, {'content': 'Answer: B \nExplanation: multidrug-resistant TB (MDR-TB)--a form of the disease caused by bacilli resistant at least to isoniazid and rifampin--occurred in 2013. Ref Harrison 19th edition pg 1103', 'role': 'assistant'}]