Until Renamed by Paul Ehrlich in the 1890s,the Heat-Labile,nonspecific Part

Until renamed by Paul Ehrlich in the 1890s,the heat-labile,nonspecific part of the immune system that enhances inflammation was known as "alexin".We now know that various proteins of this system attract neutrophils to tissues,direct phagocytosis of targets by neutrophils and macrophages,burst pathogens by insertion of the membrane attack complex (MAC) ,stimulate histamine release,and increase capillary permeability.What did Ehrlich rename this part of the immune system?

A) complement
B) contingent
C) toll-like response
D) acquired immunity
E) MBL