Give structures of the four optically active structural isomers of `C_4 H_8 O_3` (A to D) and evolve `CO_2` with aq. `NaHCO_3`. Find the structure of (A), the isomer that reacts with `LiAlH_4` to give an achiral neutralization equivalent of 74. Alcohol (B) is not oxidized with an acid solution of `Na_2 Cr_2 O_7`. What is the formula and name of the original compound?
