Major product obtained when 2-chloro-2-methyl propane is heated with sodium ethoxide is

$$\begin{gathered} 3^0 \mathrm{R}-\mathrm{X} \mathrm{undergo} \mathrm{elimination}\left({\mathrm{E}}_2\right) \mathrm{when} \mathrm{heated} \mathrm{with} \mathrm{strong} \mathrm{base}\left({\mathrm{C}}_2{\mathrm{H}}_5\mathrm{ONa}\right); \\ {\left({\mathrm{CH}}_3\right)}_3\mathrm{C}-\mathrm{Cl}+{\mathrm{C}}_2{\mathrm{H}}_5{\mathrm{O}}^{-}{\mathrm{Na}}^{+}\to {\left({\mathrm{CH}}_3\right)}_2\mathrm{C}={\mathrm{CH}}_2+{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}+\mathrm{NaCl}; \end{gathered}$$