Which of the following statements are correct?
I. The hybridisation found in cation ${\mathrm{PCl}}_4^{+}$ is sp³.
II. In AB₂L₂ type, the BAB bond angle is always greater than the normal tetrahedral bond angle. (L=Lone pairs)
III. In ClO₃^–, NH₃ and XeO₃, the hybridisation and the number of lone pairs on the central atoms are same.
IV. In discrete P₄ molecule, there are six P-P bonds and four lone pairs of electrons.