In TeCl4, the central atom tellurium involves:
Tellurium is in group 6, so it has six valence electrons. Chlorine is in group 7 so it has 7 valence electrons.
Since TeCl4 has four bond pairs and one unbounded pair, its geometry is based on the trigonal bipyramidal structure.
But since there are only four bond pairs, the molecule
takes a see-saw shape and the unbonded electrons take the place of a bonded
element.
For trigonal bipyramidal structures, the hybridization is sp3d.
Hence, option B is correct.