What is the major product Z in the given reaction sequence?
\(\left(\mathrm{CH}_3\right)_2 \mathrm{C}=\mathrm{O} \xrightarrow[\text { (2) } \mathrm{H}_3 \mathrm{O}^{+}]{\text {(1) } \mathrm{C}_2 \mathrm{H} \mathrm{MgBr}} \mathrm{X} \xrightarrow[\Delta]{\substack{\text { i) } \mathrm{SOCl}_2 \\ \text { ii) } \mathrm{CH}_3 \mathrm{ONa}}} \mathrm{Y} \xrightarrow[\text { Peroxide }]{\mathrm{HBr}} \mathrm{Z}\)
1
1-Bromo-2-methylpropene
2
2-Methoxy-2-methylbutane
3
2-Bromo-3-methylbutane
4
1-Bromo-2-methylbutane