Rheumatoid factors are immunoglobulins directed against:: (A) The Fc poion of immunoglobulin G (IgG), (B) The Fc poion of immunoglobulin A (IgA), (C) The Fc poion of immunoglobulin M (IgM), (D) The Fc poion of immunoglobulin D (IgD)
Answer is A. The Fc poion of immunoglobulin G (IgG)