In some insects, such as Drosophila, fungal cell wall elements can activate the protein Toll, which

A) acts as a receptor that, when activated, signals synthesis of antimicrobial peptides.
B) functions directly to attack the fungi presented to it.
C) produces antimicrobial peptides by interaction with chitin.
D) secretes special recognition signal molecules that identify specific pathogens.
E) causes some hemocytes to phagocytize the pathogens.