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 ailment most commonly causes periodontal disorder: 
Select and explain. 
A. Hypophosphatemia, B. Wegener's granulomatosis, C. Multiple myeloma, D. AIDS
D: AIDS
Answer: D: AIDS 
Explanation: None