Which of the following is NOT involved in antigen- antibody complexes?
This outcome reflects antibody structure, where immunoglobulin fold with antiparallel beta-sandwich provides antigen binding. Option C captures this correctly because it demonstrates immune recognition architecture, consistent with textbook descriptions and experimental observations in immunology.
Ref: Owen, Punt and Stranford, Kuby Immunology, 8th Edition, Chapter 4, Antibody Structure, covers immunoglobulin domains, beta-sheet organization and antigen binding detailing immune recognition.
