<prompt> Factor present in final common terminal complement pathway is rpt Q 38C3C4C5Protein B  <response>: Activation of the classical and alternative pathwaysleads to a common terminal pathway from C5 to C9. These complement components form the finalmembrane attack complex MAC. ... complementfixation the combining of complement with the antigen-antibody complex, rendering the complement inactive, or fixed. Ref Robbins 9e p40 