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
Which of the following mycobacteria can cause disease in HIV+ve patient with a CD4 count of 600/ cu.mm? 
Select and explain. 
A. M. tuberculosis, B. MAC, C. M. chelonei, D. M. fouitum
A: M. tuberculosis
Answer: A: M. tuberculosis 
Explanation: Ans. is 'a' i.e., M. Tuberculosis . MAC infection occurs when CD4 + T cells counts are < 50/ml, in contrast M. tuberculosis infection develops early in the course with CD4 T cells counts > 300/ml.