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 is an acid-fast bacillus 
Select and explain. 
A. Mycobacterium bacilli, B. Treponema pallidum, C. Neisseria gonorrhea, D. All of the above
A: Mycobacterium bacilli
Answer: A: Mycobacterium bacilli 
Explanation: None