This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
Complement responsible for activation of bacterial lysis is - 
Select and explain. 
A. c3a, B. c3b, C. c9, D. c5a
C: c9
Answer: C: c9 
Explanation: The MAC, which is made up of multiple copies of the final component C9, kills bacteria (especially thin-walled Neisseria) by creating pores that disrupt the osmotic balance. C3a and C5a - cause vasodilation and increased vascular permeability C3b used for opsonisation C5a also has an impoant role in chemotaxis. ref robbins 9/e pg 50_53