In which of the following molecules/ions all the bonds are not equal?? A.SF4 , SiF4. , XeF4. , BF4- WHY??

Out of the four, SF4 will not have equal bonds, because of it structure .Trigonal bipyramidal. Sulfur in SF₄ is in the formal +4 oxidation state. sulfur has total of six valence electrons, two form a lone pair. The fluorine-sulfur-fluorine bond angles are 120o in the trigonal plane and 90o to the two fluorine atoms above and below the plane.