In the following which central atom has different hybridisation than others.

Which of the following has different hybridization than other :-

The central atom assume sp^(3) hybridisation in:

The central atom assume sp^(3) hybridisation in:

Compound in which central atom assumes sp^3d hybridisation is

In which one of the following species the central atom has the type of hybridization which is not the same as that present in the other three ?