The question is missing the choices and these are CHCl3, CF4, CS2 or Br2.A polar molecule is one in which the atoms are organized such that one end of the molecule has a positive charge and the conflicting end has the opposite or negative charge. So in the given choices above, the most polar one CHCl3 this actually the only polar one in the choices. The explanation behind this is it has the same shape as CCl4 molecule, but one of the Chlorine atoms has been substituted by a Hydrogen atom. We know that Hydrogen has a weaker electronegativity in contrast to Chlorine, so electron density along the h-c bond is dragged away from the Hydrogen and in the direction of the ccl3 fragment, resulting in a polar molecule.
