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
Mycobacterium tuberculosis is differentiated from other atypical mycobacteria by: 
Select and explain. 
A. Niacin test, B. AFB staining, C. PAS staining, D. None
A: Niacin test
Answer: A: Niacin test 
Explanation: Ans. is. 'a' i. e., Niacin test