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
Periodontitis is usually severe in patients: 
Select and explain. 
A. Taking phenytoin, B. With defective neutrophils, C. With bruxism, D. With overcrowding
B: With defective neutrophils
Answer: B: With defective neutrophils 
Explanation: None