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
Of the following four bacterial species, which is LEAST
LIKELY to be found in plaque? 
Select and explain. 
A. Actinomyces viscosus, B. Streptococcus mutans, C. Streptococcus salivarius, D. Streptococcus sanguis
C: Streptococcus salivarius
Answer: C: Streptococcus salivarius 
Explanation: None