Sodium fusion extract, obtained from aniline, on treatment with iron (II) sulphate and H2SO4 in presence of air gives a
Prussian blue precipitate. The blue colour is due to the formation of
(A) Fe4[Fe(CN)6]3 (B) Fe3[Fe(CN)6]2
(C) Fe4[Fe(CN)6]2 (D) Fe3[Fe(CN)6]3