(i) An aqueous solution of a compound (A) is acidic towards litmus and (A) sublimes at about `300^(@)C`.
(ii) (A) on treatment with an excess of `NH_(4)SCN` gives a red coloured compound (B) and on treatment with a solution of `K_(4)[Fe(CN)_(6)]` gives a blue coloured compound (C).
(iii) (A) on heating with excess of `K_(2)Cr_(2)O_(7)` in the presence of concentrated `H_(2)SO_(4)` evolves deep red vapours of (D).
(iv) On passing the vapour of (D) into a solution of NaOH and then adding the solution of acetic acid and lead acetate, a yellow precipitate of compound (E) is obtained.
Identify (A) to (E) and give chemical equations for the reactions.

Options

A. `+VI`
B. `+V`
C. `+III`
D. `-II`

Answer

A