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
The most common organism involved in a periapical abscess is: 
Select and explain. 
A. Strep. pyogens, B. Strep. viridans, C. β hemolytic streptococci, D. Non hemolytic streptococci
A: Strep. pyogens
Answer: A: Strep. pyogens 
Explanation: None