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 plaque is most harmful and causes spread of Inflammation to the connective tissue leading to bone destruction: 
Select and explain. 
A. Subgingival epithelial attached, B. Subgingival unattached, C. Subgingival plaque, D. Supragingival plaque
A: Subgingival epithelial attached
Answer: A: Subgingival epithelial attached 
Explanation: None