Principal functional group is ketone. $\therefore {\mathrm{C}}_1$ is carbonyl carbon atom. Locants for hydroxyl groups and double bonds are 5 and $2,$ which are preferred over 3 and 5, since the lower number at first difference (2 compared to 3 ) is preferred. Hence, the IUPAC name of given compound is 5 -hydroxycyclohex-2-en-

1 -one.