Two aldopentoses X and Y give the same osazone derivative. X is oxidized to an optically active aldaric acid by dilute nitric acid. Ruff degradation of Y gave a tetrose which was similarly oxidized to an optically active aldaric acid. Assign the structures of X and Y from the following list? Circle the correct choices and clearly label them as X and Y HOH H OH HO H H OH H2OH OH HO-H HO H H OH H OH HFOH CH2OH H OH CH2OH H- OH CH2OH 1 3. 4