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: Unknown
Which of the following is a Opsonin? 
Select and explain. 
A. C3a, B. C3b, C. C5a, D. LTC4
B: C3b
Answer: B: C3b 
Explanation: Ref. Robbins Pathology. 9th edition. Page. 78
 
Examples of opsonins include:

Antibodies:
	
IgG and IgA


Components of the complement system:
	
C3b, C4b, and iC3b


Mannose Binding Lectin (MBL)
Membrane Attack Complex (MAC)