单项选择题

A.尿IgG/血Tf)/(尿Tf/血IgG)
B.尿IgG/血IgG)/(尿Tf/血Tf)
C.血IgG/尿IgG)/(血Tf/尿Tf)
D.尿Tf/尿IgG)/(血Tf/血IgG)
E.尿IgG/血IgG)/(血Tf/尿Tf)