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
Most striking feature of aggressive periodontitis which differentiates it from other types. 
Select and explain. 
A. No local factors of inflammation present., B. No systemic factors of inflammation present., C. Both local and systemic factors of inflammation present., D. None of the above.
A: No local factors of inflammation present.
Answer: A: No local factors of inflammation present. 
Explanation: None