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
The predominant immunoglobulin in sulcular fluid is: 
Select and explain. 
A. Ig A, B. Ig G, C. Ig M, D. Ig E
B: Ig G
Answer: B: Ig G 
Explanation: None