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
The PHP index describes: 
Select and explain. 
A. Performance of hygiene by patient after brushing self evaluation, B. Measures oral hygiene and gingival bleeding, C. Score the plaque surface after treatment, D. Measures the oral flora and plaque index
A: Performance of hygiene by patient after brushing self evaluation
Answer: A: Performance of hygiene by patient after brushing self evaluation 
Explanation: None