The number of $\sigma$ and $\pi$-bonds between two carbon atoms in $CaC_2$ is

Question

$\begin{array}{1 1}(a)\;\text{one }\pi\text{-bond and one }\sigma\text{ bond}\\(b)\;\text{two }\sigma\text{-bonds and one }\pi\text{ bond}\\(c)\;\text{two }\pi\text{-bonds and one }\sigma\text{ bond}\\(d)\;\text{three }\sigma\text{-bonds and no }\pi\text{ bond}\end{array}$