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: Pathology
Complement-mediated lysis is mediated by - 
Select and explain. 
A. IgM, B. IgE, C. IgA, D. IgD
A: IgM
Answer: A: IgM 
Explanation: The classical activation pathway activated by antigen/antibody immune complexes. Antigen involved is IgM or IgG
Other pathways of the complement system
a) The mannose-binding lectin activation pathway activated by microbes with mannose terminal groups.
b) The alternative activation pathway activated by microbes or tumor cells.
c) The terminal pathway that is common to first three pathways and leads to the membrane attack complex that lyses cells.