Answer:
The correct answer is option d.
Explanation:
A section of the complement system of defense is opsonization. It is a term that signifies towards an immune procedure where the constituents like bacteria are focused for elimination by an immune cell called phagocyte.
In the process of opsonization, the exterior of the pathogen gets coated so that it can be determined easily by the host's phagocytes. The opsonins are the constituents, which when coated on the pathogens will develop some kind of handles over them so that the phagocyte can trap them easily.
