The major product obtained on treatment of $CH_3CH_2CH(F)CH_3$ with $CH_3 O^{-} /CH_3OH $ is :

Question

$\begin{array}{1 1} CH_3CH_2CH(CH_3)CH_3 \\ CH_3cH = CHCH_3 \\ CH_3CH_2CH = CH_2 \\ C_6H_5COOCH \end{array} $