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 Antibody has highest molecular weight 
Select and explain. 
A. IgG, B. IgE, C. IgD, D. IgM
D: IgM
Answer: D: IgM 
Explanation: IgM has highest molecular weight.