Hydrocarbons

Identify product \((Z)\) in the series, of reaction

\(\mathrm{CH}_2=\mathrm{CH}_2 \xrightarrow{\mathrm{HBr}} X \xrightarrow{a q . \mathrm{KOH}} Y \xrightarrow[\mathrm{I}_2 \text { excess }]{\mathrm{Na}_2 \mathrm{CO}_3} Z\)