A compound `(X)` with the molecular formula `C_6 H_10 O_4` is a neutral liquid. On heating `(X)`, under reflux with aqueous sodium hydroxide and distilling the product. A colourless liquid is obtained which on warming with iodine and aqueous sodium hydroxide gives a pale yellow precipatate `(Y)`. The residue in the distilling flask is the sodium salt of an acid `(Z)`, which decolourises aqueous acidified potassium permaganate `(VII)` on heating. Identify `(X), (Y)`, and `(Z)` and give all the reactions involved.

Explanation

.