The Importance of Complement Activation as an Innate Immune Defense

The importance of complement activation as an innate immune defense against infections is illustrated by:

A) The evolution of complement avoidance strategies by many pathogens
B) The large number of proteins involved in the complement pathway
C) The large number of complement regulatory pathways expressed by the host
D) The existence of three different mechanisms for initiating complement activation
E) The ability of the membrane attack complex to lyse some pathogens