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
Score 6 of Russet's index is? 
Select and explain. 
A. 1/2 bone loss and 1/2 root involvement, B. Advanced bone loss, 1/2root involved, C. Calculus, D. Mild gingivitis
A: 1/2 bone loss and 1/2 root involvement
Answer: A: 1/2 bone loss and 1/2 root involvement 
Explanation: None