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
Not found commonly in a periapical lesion 
Select and explain. 
A. Pseudomonas, B. Streptococcus, C. porphyromonas, D. All of the above
A: Pseudomonas
Answer: A: Pseudomonas 
Explanation: The microbiota in periapical region is dominated by anaerobes. Streptococcous are thus not common in periradicular lesions
cohen 10th ed pg 575. 576.
Streptococci are predominant in intraradicular lesions.