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
When the black band of a CPITN probe is completely visible while in gingival sulcus, it means 
Select and explain. 
A. The individual has advanced periodontal disease, B. The individual has pockets between 4 and 5 mm, C. The individual needs comprehensive periodontal surgery, D. The individual has calculus and needs scaling and oral hygiene instructions
D: The individual has calculus and needs scaling and oral hygiene instructions
Answer: D: The individual has calculus and needs scaling and oral hygiene instructions 
Explanation: None