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 teeth are least involved in periodontitis? 
Select and explain. 
A. Lower incisor and lower molar, B. Lower premolar and upper canine, C. Upper molars and upper incisors, D. Lower incisors and upper molars
B: Lower premolar and upper canine
Answer: B: Lower premolar and upper canine 
Explanation: None