Final answer:
C-reactive peptide binds to peptidoglycan and mannose-binding lectin binds to carbohydrate residues on bacterial surfaces. The correct answer is b) Peptidoglycan; Carbohydrate.
Step-by-step explanation:
C-reactive peptide is an opsonin that binds to peptidoglycan on bacterial surfaces and can activate complement. Mannose-binding lectin acts as an opsonin by binding carbohydrate residues on bacterial cell surfaces and can activate complement.
Opsonization is the coating of a pathogen with molecules, such as complement factors, C-reactive protein, and serum amyloid A, to assist in phagocyte binding to facilitate phagocytosis. IgG antibodies also serve as excellent opsonins, binding their Fab sites to specific epitopes on the surface of pathogens.