有关脑脊液中Ig浓度，说法正确的是

A.IgG＞IgM＞IgA

B.IgG＞IgA＞IgM

C.IgM＞IgG＞IgA

D.IgM＞IgA＞IgG

E.IgA＞IgM＞IgG