Select saponification reaction from the following :

$\displaystyle \mathrm{C}_{4} \mathrm{H}_{9} \mathrm{OH} \xrightarrow[\mathrm{KMnO}_{4}]{\text { Alkaline }} \mathrm{C}_{3} \mathrm{H}_{7} \mathrm{COOH}$

$\displaystyle 2 \mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}+2 \mathrm{Na} \longrightarrow 2 \mathrm{C}_{2} \mathrm{H}_{5} \mathrm{COONa}+\mathrm{H}_{2}$

$\displaystyle \mathrm{CH}_{3} \mathrm{COOC}_{2} \mathrm{H}_{5}+\mathrm{NaOH} \longrightarrow \mathrm{CH}_{3} \mathrm{COONa}+\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}$

$\displaystyle \mathrm{CH}_{3} \mathrm{COONa}+\mathrm{NaOH} \longrightarrow \mathrm{CH}_{4}+\mathrm{Na}_{2} \mathrm{CO}_{3}$