How does the number of moles of solute before a dilution compare with the number of moles of solute after the dilution?

The quantity of moles of a solute won't change as an answer is weakened, be that as it may, the centralization of the solute will diminish. If you somehow happened to dissipate the water from the weakened arrangement, you would have an indistinguishable number of moles of solute from when you began. You can test this by looking at the mass of the solute before creating the answer for the mass of the solute after the arrangement was weakened. The two masses ought to be the same.

The correct answer is  "c".  it is "c" because melting is an endothermic change, and endothermic get's energy from surroundings.