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
Actinobacillus actinomycetamcomitans is commonly associated with 
Select and explain. 
A. Juvenile periodontitis, B. Adult periodontitis, C. Refractory periodontitis, D. All the above
A: Juvenile periodontitis
Answer: A: Juvenile periodontitis 
Explanation: None