This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2019, Subject name: Microbiology
[{'content': 'Which antibody is seen in recent infection? \nSelect and explain. \nA. IgM, B. IgG, C. IgE, D. IgD', 'role': 'user'}, {'content': 'Answer: A \nExplanation: IgM IgM is Pentavalent Ig It has max molecular weight It has max sedimentation coefficient IgM is produced first in immune response 1st to appear following infection, indicates recent infection IgM plays a role in: - Opsonisation Classical complement pathway IgM & IgD are not present over B cell surface', 'role': 'assistant'}]