An aromatic compound 'A' on treatment with and KOH gives two compounds, both of which gives same product 'B' when distilled with zinc dust. Oxidation of 'B' gives 'C' with molecular formula
. Sodium salt of 'C' on heating with soda lime gives 'D' which may also be obtained by distilling 'A' with Zinc dust. Identify 'A', 'B', 'C' and 'D'.