1-Butyne on oxidation with hot alkaline $KMnO_4$ would yield

Question

$\begin{array}{1 1}(a)\;CH_3CH_2CH_2COOH\\(b)\;CH_3CH_2COOH\\(c)\;CH_3CH_2COOH+CO_2+H_2O\\(d)\;CH_3CH_2COOH+HCOOH\end{array}$