A white precipitate (X) is formed when a mineral (A) is boiled with `Na_(2)CO_(3)` solution. The precipitate is filtered and filtrate contains two compound (Y) and (Z). The compound (Y) is removed by
crystallization and when `CO_(2)` is passed through the filtrate obtained after crystallization, then `(Z)` changed to `(Y)`. When compound (Y) is heated, it gives two compounds (Z) and (T). Compound (T) on heating with cobalt oxide produces blue coloured substance (S)
When cobalt oxide is heated with (Y), then a bead (S) is formed which is blue in colour. The bead (S) is
A. `CoCO_(3)`
B. `Co(BO_(2))_(2)`
C. `CoO`
D. `B_(2)O_(3)`
