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
All the following are Acid - fast except 
Select and explain. 
A. M.TB, B. M.Leprae, C. Isospora, D. M.Avium complex
D: M.Avium complex
Answer: D: M.Avium complex 
Explanation: M.TB, M.leprae, Isospora cyclospora & Nocardia are acid fast.