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
Under the RNTCP, for diagnosis of MDR TB, currently drug sensitivity testing is done for: 
Select and explain. 
A. Rifampicin, B. Rifampicin, Isoniazide, C. Rifampicin, Isoniazide and Ethambutol, D. Rifampicin, Isoniazide and Pyrazinamide
C: Rifampicin, Isoniazide and Ethambutol
Answer: C: Rifampicin, Isoniazide and Ethambutol 
Explanation: Presently conventional solid egg-based Lowenstein-Jensen (LJ) media will be used for primary culture at the RNTCP accredited laboratory. DST will be performed for streptomycin (S), isoniazid (H), rifampicin (R) and ethambutol (E) only. Pyrazinamide (Z) sensitivity testing may be included at a later period of DOTS-Plus implementation. Ref: