This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
The most avidly complement fixing antibody is - 
Select and explain. 
A. IgA, B. IgG, C. IgM, D. IgE
B: IgG
Answer: B: IgG 
Explanation: IgG is the main serum immunoglobulin consisting of 80% of the total. equally distributed between intravascular and extravascular compaments. IgG paicipates in most immunological reactions such as complement fixation, precipitation a, d neutralization toxins and virus. REF:Anathanarayan & paniker's 9th edition, pg no:97 <\p>