Answer:
The correct answer is Cb3 protein.
Explanation:
The alternative pathway of complement is the immune system's natural defense system against any infectious agent. It is one of the 3 complement pathways that kills and any pathogen that enters our body.
The pathway is activated when Cb3 protein binds directly to the microbe.
Cb3 protein is found in abundant quantity in our plasma. It is available in the free form.
