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, sputum culture for MDR TB is to be examined for at least: 
Select and explain. 
A. 4 weeks, B. 8 weeks, C. 10 weeks, D. 12 weeks
B: 8 weeks
Answer: B: 8 weeks 
Explanation: All cultures should be examined 48-72 hours after inoculation to detect gross contaminants. Thereafter cultures are examined weekly, up to 8 weeks on a specified day of the week. Ref: