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: Microbiology
Which immunoglobulin possess highest carbohydrate content? 
Select and explain. 
A. IgG, B. IgA, C. IgD, D. IgM
C: IgD
Answer: C: IgD 
Explanation: IgD possess highest carbohydrate content.