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
Which of the following complement component can be activated in both common as well as alternate pathways? 
Select and explain. 
A. C1, B. C2, C. C3, D. C4
C: C3
Answer: C: C3 
Explanation: The complement proteins can be activated by 3 pathways;
Classical,lectin and alternate pathways. Terminal pathway is common to the first three pathways and is present ar the level of the post-activation stage of C3. It eventually leads to the membrane attack complex that lyses cells.