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
Which of the following is the most likely source of collagenase? 
Select and explain. 
A. Staphylococcus aureus, B. Bacteroides gingivalis, C. Treponema microdentum, D. Veillonella alkalescens
B: Bacteroides gingivalis
Answer: B: Bacteroides gingivalis 
Explanation: None