An organic compound 'A' with the molecular formula C4H8O2 was hydrolyzed with dil. H2SO4 to give a carboxylic acid 'B' and an alcohol 'C'. 'C' on dehydration gives ethene, and 'C' also on oxidation gives back 'B'. Identify 'A', 'B', and 'C' and write the chemical equations for the reactions involved.