An organic compound `(A), C_(8)H_(4) O_(3)` in dry benzene in the presene of anhydorus `AlCl_(3)` gives compound `(B)`. Compound `(B)` on treatment with `PCl_(5)` followed by reaction with `H_(2)//Pd (BaSO_(4))` gives compound `(C)` which on reaction with hydrazine gives a cyclised compound `(D),(C_(14) H_(10) N_(2))` Idenyify `(A),(B),(C)` and `(D)`. Explain the formation of `(D)` from `(C)`.
