An organic compound A with molecular formula C7H7NO reacts with Br2/aq. KOH to give compound B, which upon reaction with NaNO2 and HCl at 0°C gives C. Compound C on heating with CH3CH2OH gives a hydrocarbon D. Compound B on further reaction with Br2 water gives white precipitate of compound E. Identify the compound A, B, C, D and E; also justify your answer by giving relevant chemical equations.