15. Which of the following molecule is not included in C5 convertase of the classical pathway and alternative pathway? A. C5b B. C4b C. C2b D. C3b E. Bb 16. Red blood cells can carry immune complex (antigen-antibody complex) in the circulation to the liver. At there, they can be removed by the kupffer cell. The molecule expressed on RBC and involve in carrying the immune complex is A. factor P B. poly lg-R C. CRN D. FcRn E. MCP (membrane cofactor protein) 17. Which of the following events occur first when pathogens invade the host? A. classical pathway of complement activation B. lectin pathway of complement activation C. alternative pathway of complement activation D. naive T cells are activated and differentiate to Th1 cells E. produce IgG antibody 18. Which of the following molecules that do not contain ITAM in their cytoplasmatic tail? A. lg/lg B. CD19 C. FcyR-II B D. CD3 E. CD28 19. Which of the following events is not appropriate for description of response toward TD-Ag? A. generate memory B cells B. produce long-lived plasma cells C. class switching.