This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti Microbial, Subject name: Pharmacology
If somebody develops resistance to INH, patient will develop simultaneously resistance to which drug? 
Select and explain. 
A. Streptomycin, B. Rifampicin, C. Ethambutol, D. Pyrazinamide
B: Rifampicin
Answer: B: Rifampicin 
Explanation: Ref: KD Tripathi, 7th ed. pg. 767* Rifampicin is considered as effective as isoniazid. This agent is active against slow and intermittently dividing bacterium (spurters).* If someone develops resistance to INH, they are most likely to develop resistance to rifampicin as well.* In MDR-TB, there is resistance to INH and rifampicin.