Social & Preventive Medicine As per RNTCP guidelines, Multi drug resistance (MDR) TB is defined as resistance to: A Rifampicin B Rifampicin and isoniazide C Rifampicin, isoniazide and ethambutol D None of the above 💡 Explanation As per RNTCP guidelines, Multi drug resistance (MDR) TB is defined as resistance to: ✓ Correct Answer: B. Rifampicin and isoniazide