Which of the following has double bond and both the bonds are $\mathrm{\pi }-\mathrm{bonds}?$

$$\begin{gathered} {\mathrm{C}}_2\left(\mathrm{Z}=6\right):{ \left(\mathrm{\sigma }1\mathrm{s}\right)}^2,{ \left(\mathrm{\sigma }*1\mathrm{s}\right)}^2,{ \left(\mathrm{\sigma }2\mathrm{s}\right)}^2,{ \left(\mathrm{\sigma }*2\mathrm{s}\right)}^2,{ \left(\mathrm{\sigma }2{\mathrm{p}}_{\mathrm{x}}\right)}^2={\left(\mathrm{\pi }2{\mathrm{p}}_{\mathrm{y}}\right)}^2 \\ \mathrm{B}.\mathrm{O}.=\frac{1}{2}\left(8-4\right)=2 \end{gathered}$$

${\mathrm{C}}_2$ has last 4 electrons for double bond in $\mathrm{\pi }$-orbitals. hence ${\mathrm{C}}_2$ has double bond made of two $\mathrm{\pi }$-bonds.