Solve this: 

175. An alkyl chloride produces a singlealkene on reaction with sodium ethoxide and ethanol. The alkene further undergoes hydrogenation to yield 2-methyl-butane. The unknown alkyl  chloride is 

$$\begin{gathered} \left(1\right) ClC{H}_{2}CH\left(C{H}_3\right)C{H}_{2}C{H}_3 \\ \left(2\right) ClC{H}_{2}C\left(C{H}_3{)}_{2}C{H}_3 \\ \right(3) ClC{H}_{2}C{H}_{2}C{H}_{2}C{H}_3 \\ (4) C{H}_{3}C(Cl\left)\right(C{H}_3)C{H}_{2}C{H}_3 \end{gathered}$$