Solution :
Symmetrical molecules are generally non-polar although they have polar bonds. This is because bond dipole of one bond is cancelled by that of the other. $$B{F_3},Si{F_4}\,{\text{and}}\,Xe{F_4}$$ being symmetrical as non-polar. $$S{F_4}$$ is unsymmetrical because of the presence of a lone pair of electrons. Due to which it is a polar molecule.
Releted MCQ Question on Inorganic Chemistry >> Chemical Bonding and Molecular Structure
Releted Question 1
The compound which contains both ionic and covalent bonds is