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
Diarrhoea in AIDS can be caused by all of the following organisms, EXCEPT: 
Select and explain. 
A. Mycobacterium, B. Cryptosporidium, C. Cytomegalovirus, D. None of the above
D: None of the above
Answer: D: None of the above 
Explanation: Common enteric pathogens often cause a more severe and protracted diarrheal illness in persons with AIDS. Oppounistic infections causing diarrhoea in AIDS: Mycobacterium species Viruses (cytomegalovirus, adenovirus, and herpes simplex) Protozoa (Cryptosporidium, Isospora belli, Microsporida, and Blastocystis hominis) may also play a role Agents transmitted venereally per rectum (e.g., Neisseria gonorrhoeae, Treponema pallidum, Chlamydia) may contribute to proctocolitis. Ref: Camilleri M., Murray J.A. (2012). Chapter 40. Diarrhea and Constipation. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e.