What is the relationship between smoking and periodontal diseases?

Smoking is among the most important risk factors in the incidence and progression of periodontal diseases.
Smoking has a negative effect on all periodontal therapeutic approaches.
In almost all forms of periodontal disease, both the anaerobic periodontal microbiota and the host response play crucial roles in the onset and progression of these diseases.
The concentration of tobacco has a direct reaction in the host response.
a) I and II are correct.
b) II, III, and IV are correct.
c) I, III, and IV are correct.
d) All statements are correct.