Final answer:
C-reactive protein is an acute phase response protein that is part of the innate immune system, enhancing phagocytosis and activating the classical complement pathway.
Step-by-step explanation:
C-reactive protein (CRP) is classified as an acute phase response protein. It is produced by the liver and its levels increase in response to inflammation. It is part of the innate immune system and plays a key role in opsonization, which enhances phagocytosis of pathogens, and also in complement activation by the classical pathway when it binds to the surface of a pathogen. CRP is not a cytokine, chemokine, surfactant, or cell-adhesion molecule.
In the context of the complement system and acute-phase proteins, identify the pathway triggered by the binding of an acute-phase protein like CRP to a pathogen. The correct answer is A. classical complement activation pathway, which is one of the ways the body can trigger a rapid response to pathogens using pre-formed components in blood plasma.