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 test is the test of Integrity of PDL: 
Select and explain. 
A. Percussion test., B. Thermal test., C. Mobility depressibilty testing., D. EPT.
A: Percussion test.
Answer: A: Percussion test. 
Explanation: PERCUSSION test → is the test of INTEGRITY of Pdl