A molecule (X) has (i) four sigma bonds formed by the overlap of  ${\mathrm{sp}}^2$ and s orbitals; (ii) one sigma bond formed by ${\mathrm{sp}}^2$and ${\mathrm{sp}}^2$orbitals and (iii) one $\pi$ bond formed by ${\mathrm{P}}_{\mathrm{z}}$and ${\mathrm{P}}_{\mathrm{z}}$orbitals. Which of the following is X?

$\mathrm{\pi }$-bond is formed in the case of an unsaturated compound. So, out of all the given options only${\mathrm{C}}_2{\mathrm{H}}_4$ contains $\mathrm{\pi }$-bond.

So it has four sigma bonds formed by the overlap of ${\mathrm{sp}}^2$ and S orbitals, one sigma bond formed by ${\mathrm{sp}}^2$ and ${\mathrm{sp}}^3$ orbitals and one π bond formed by ${\mathrm{P}}_{\mathrm{x}}$ and ${\mathrm{P}}_{\mathrm{Z}}$ orbitals.