An organic compound (A) `C_8 H_4 O_3` , in dry bebzene in the presence of anhydrous `AlCl_3` gives compound (B ). The 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 cyclide compound (D) `(C_(14) H_(10) N_2)`. Identify (A), (B) (C ), and (D) Explain the formation of (D ) from (C ).