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
Bacteria found in gingivitis are localized in 
Select and explain. 
A. Connective tissue fibres, B. Gingival sulcus, C. Alveolar bone, D. Periodontal ligament
B: Gingival sulcus
Answer: B: Gingival sulcus 
Explanation: None