Why are many opsonins multimeric?
A. Because they are all derived from the same proto-opsonin
B. Because they bind repeating structures on pathogen surfaces
C. So that they can be regulated allosterically
D. Because they have to crosslink receptors on phagocytes in order for phagocytosis to occur
E. Because one subunit binds pathogen and the other has enzymatic activity
Answer: B