Which of the following molecules is non-polar in nature?

A molecule is non-polar if its net dipole moment ($\mu$) is zero. This happens in symmetric structures where individual bond dipoles cancel out.${\text{SbCl}}_5$ has a trigonal bipyramidal geometry ($s{p}^{3}d$). In this symmetric arrangement:Three equatorial $\text{Sb-Cl}$ bond dipoles cancel each other at $120^{\circ }$.Two axial $\text{Sb-Cl}$ bond dipoles cancel each other at $180^{\circ }$.Thus, net $\mu =0$. Others are unsymmetrical (${\text{NO}}_2$ is bent, others have different atoms attached).