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
Commonest mycobacterial infection in patient in tropical countries - 
Select and explain. 
A. M. Leprae, B. M. avium intracellulare, C. M. tuberculosis, D. M. kansasii
C: M. tuberculosis
Answer: C: M. tuberculosis 
Explanation: None