For this example, we have to identify the intermolecular forces present in both the solute and the solvent. Here it's safe to assume either one is the solute or the solvent. And predict whether a solution will form between the two.
So, again remember fundamentally, for a solution to form, both should be polar or both should be non-polar. If they are the same in polarity, they will mix together to form a solution. If we take a look at the first one, we have CCl4 and P4. Well, P4 is the easy one. We say that anytime we have non-metals connected to themselves or by themselves, they are non-polar by default. If you are non-polar, your intermolecular forces are London dispersion. That's not as important. Fundamentally, we need to just know if it's polar or non-polar here.
CCl4: We've drawn this already. Remember, C goes in the center. It has 4 valence electrons. We have 4 chlorines, each one has 7 valence electrons. The central element has no lone pairs so we use rule 1a: The central element must be connected to the same elements, which it is. And the central element must be less electronegative than the surrounding elements. So it follows rule 1a and 1b. Therefore, it is definitely non-polar.
Now, because both are non-polar, they will form a solution. We could also say that since they are both non-polar, they both exhibit London dispersion forces.
So, if we have to identify the intermolecular force, we'd say both are London dispersion.