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
When P.D. probing in gingivitis done, depth is measured
from 
Select and explain. 
A. Base of pocket to CD, B. Base of pocket to free marginal gingiva, C. Marginal gingiva to CEJ, D. Junctional epithelium to free gingival margin
B: Base of pocket to free marginal gingiva
Answer: B: Base of pocket to free marginal gingiva 
Explanation: None