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
Bacteria, which are not found in normal healthy periodontium, are: 
Select and explain. 
A. Actinomyces, B. Capnocytophaga, C. Veillonella, D. Eubacterium
D: Eubacterium
Answer: D: Eubacterium 
Explanation: None