This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: RNTCP, Subject name: Social & Preventive Medicine
In a suspected TB patient, two boxes are given for sputum sample collection. They are labeled as:- 
Select and explain. 
A. a, b, B. A, B, C. 1, 2, D. Y, Z
A: a, b
Answer: A: a, b 
Explanation: - 2 sputum samples over a period of 2 days is collected in pts, with history of cough > 2weeks. - Spot sample is collected on Day-1; Morning sample is collected on Day-2. Labeling of sputum samples in RNTCP: Diagnosis as well as follow-up samples are labeled with a single LSN with a suffix 'a' for the spot sample and 'b' for morning sample.