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: Social & Preventive Medicine
Multidrug resistance in TB is defined as resistance to 
Select and explain. 
A. Streptomycin, Rifampicin and Isoniazid, B. Isoniazid and Rifampicin, C. Streptomycin and Rifampicin, D. Streptomycin and Isoniazid
B: Isoniazid and Rifampicin
Answer: B: Isoniazid and Rifampicin 
Explanation: Multidrug Resistant TB (MDR-TB): Resistance to Isoniazid and Rifampicin “with or without resistance to other drugs‘

Treatment of MDR-TB must be done on the basis of sensitivity testing
Directly observed therapy certainly helps to improve outcomes and should be considered an integral part of the treatment of MDR-TB.

Extensive Drug Resistant TB (XDR–TB): Resistance to rifampicin and isoniazid as well as to any member of the quinolone family and at least one of the following second-line TB.
TB treatments: kanamycin, capreomycin, or amikacin.