The correct option is
C SeF4 and
CH4 have same shape
SeF4 with
sp3d hybridization is see-saw whereas
CH4 with
sp3 is tetrahedral.
I+3−sp3, lone pair = 2; bond pair= 2, thus, shape is bent.
The extent of overlapping of d-orbital of phosphorus and 1s-orbital of hydrogen is very less because the energy difference between them is too high for favourble bond formation so that the most of 1s-orbital of hydrogen interacts with p-orbitals to form
PH3.
PH5 does not exist as d-s orbital overlapping is less, it will dissociate into
PH3 and
H2.
In case of
BiCl5, it is due to the inert pair, +5 oxidation state is not stable.
In
SO2, both
pπ−pπ and
pπ−dπ bonds are present because S is a third period element and has favourable energy difference for
pπ−dπ overlap between
S and
O.
Hence, option (c) is the correct answer.