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
Predominant bacteria found in two days old plaque 
Select and explain. 
A. Streptococci, B. Bacteroides, C. Spirocheates, D. Actinomyces
A: Streptococci
Answer: A: Streptococci 
Explanation: None