Which of the Following Events Initiates Activation of the Alternative

Multiple Choice

Which of the following events initiates activation of the alternative complement pathway?

A) C1q binding to a microbial surface
B) Mannose-binding lectin (MBL) binding to a microbial surface
C) Complement receptor 1 (CR1) binding of C3b
D) Factor I cleavage of C3
E) Spontaneous cleavage of C3 to C3b