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: Pathology
Protective species or non cariogenic bacteria among the following is/are: 
Select and explain. 
A. Veillonella., B. Capnocytophega., C. Streptococcus mitis., D. Both AB
D: Both AB
Answer: D: Both AB 
Explanation: None