A molecule (X) has

(i) four sigma bonds formed by the overlap of ${\mathrm{sp}}^2$ and $\mathrm{s}$ orbitals;

(ii) one sigma bond formed by ${\mathrm{sp}}^2$ and ${\mathrm{sp}}^3$ orbitals and

(iii) one $\mathrm{\pi }$ bond formed by ${\mathrm{P}}_{\mathrm{x}}$ and ${\mathrm{P}}_{\mathrm{z}}$ orbitals.

Which of the following is $\mathrm{X}$ ?

 $\mathrm{\pi }$-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 $\pi$ bond formed by ${\mathrm{P}}_{\mathrm{x}}$ and ${\mathrm{P}}_{\mathrm{Z}}$ orbitals.