In the Complement Fixation Test, the Presence of an Antibody/antigen

Multiple Choice

In the complement fixation test, the presence of an antibody/antigen reaction is detected because

A) it precipitates complement proteins.
B) complement C5-9 are consumed in the specimen.
C) complement is bound and is unavailable to lyse sensitized red blood cells.
D) complement is activated and it lyses red blood cells.
E) complement C3 is consumed in the specimen.