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

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

Anti-Markownikoff's addition of $$\mathrm{HBr}$$ is observed in

In acetylene molecule between the carbon atoms there are

The reaction of C₆H₅CH = CHCH₃ with HBr produces