Solution :
We know, In an electrolyte solution, the number of dissolved particles is larger because the solute breaks apart into ions. The greater the number of ions, the larger the impact on colligative properties will be.
So, the compound which will dissociate into more number of electrolyte has more vapour pressure.
Out of all given compound K₃PO₄ have highest number of particles after dissociation.
Hence, D) is the required solution.
