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: Dental
Localized Juvenile Periodontitis- primary pathogen is 
Select and explain. 
A. Acinobacillus Actinomycetemcomitans, B. Prevotella intermedia, C. Mycoplasma, D. all the above
D: all the above
Answer: D: all the above 
Explanation: None