The order of increasing polarity in HCl, $\mathrm{CO}_{2}$ , $\mathrm{H}_{2}\mathrm{O}$ and HF molecules is

Polarity depends on the net dipole moment of the molecule. $\mathrm{CO}_{2}$ is linear, so the two bond dipoles cancel and its polarity is zero. For the others, the approximate dipole moments increase as: $$\mathrm{HCl} < \mathrm{HF} < \mathrm{H_2O}$$ This is because $\mathrm{H_2O}$ has a bent shape, so its bond dipoles add to give a larger net dipole moment than $\mathrm{HF}$. Therefore, the increasing order is: $$\mathrm{CO}_{2} < \mathrm{HCl} < \mathrm{HF} < \mathrm{H_2O}$$ Now compare with the given options. This matches option $\mathrm{C}$.