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: Microbiology
True regarding mycobacterium tuberculosis is ? 
Select and explain. 
A. Produces visible colonies in 1 weeks time on Lowenstein-Jensen media, B. Decolorised by 20% sulfuric acid, C. Facultative aerobe, D. Niacin positive
D: Niacin positive
Answer: D: Niacin positive 
Explanation: Ans. is 'd' i.e., Niacin positive