What happen when a solution of potassium chromate is treated with an excess of dil. Nitic acid?
A. `Cr^(3+)`and `Cr_(2)O_(7)^(2-)` are formed
B. `Cr_(2)O_(7)^(2-)` and `H_(2)O` are formed
C. `CrO_(4)^(2-)` is reduced to `Cr^(3+)`
D. `CrO_(4)^(2-)` is oxidised to `Cr_(2)O_(7)^(2-)`