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
Multi drug resistant T.B is defined as resistance to 
Select and explain. 
A. INH and pyrizinamide, B. INH and Rifampicin, C. Rifampicin and Pyrizinamide, D. Resistance to all first line of drugs
B: INH and Rifampicin
Answer: B: INH and Rifampicin 
Explanation: 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