Astrokel gave a very good hint.
Here we will follow the universal rule that
Like dissolves Like.
The solvent in question is CCl
4. It is a very good example of
Non-Polar Solvent.
Now out of four, if you see the first three options : all of them are metal compounds. So a clear demarcation of
Cation and
Anion. Obviously they will then be quite polar in nature and thus won't get along well with CCl
4!!.
PCl
3 has very little dipole moment due to nullifying effect of the dipole moment vector of three chloride ions. Though it has a little bit of dipole moment due to lone pairs of electrons on phosphorus. Therefore it can now dissolve in CCl
4...
without any TENSION !!!