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 teeth are affected in Generalised periodontitis? 
Select and explain. 
A. Incisors, B. Molars, C. Incisors, 1st molars and 3 other teeth., D. None of the above
C: Incisors, 1st molars and 3 other teeth.
Answer: C: Incisors, 1st molars and 3 other teeth. 
Explanation: None