Which of the Following Most Accurately Describes How Foreign Substances

Multiple Choice

Which of the following most accurately describes how foreign substances can activate complement?

A) Antibodies can bind to foreign antigens and activate complement through the classical pathway.
B) Foreign substances can bind to spontaneously activated C3 and stabilize it.
C) Foreign proteins bind to C1 and activate it.
D) Foreign proteins are phagocytized by macrophages and directly activate complement.
E) Both "Antibodies can bind to foreign antigens and activate complement through the classical pathway" and "Foreign substances can bind to spontaneously activated C3 and stabilize it" are correct.