The freezing point of a solution is

A. lower than the freezing point of the solvent alone because higher temperature is required to accelerate solvent molecular motion enough to overcome obstructon by solute particles..

B. lower than the freezing point of the solvent alone because lower temperature is required to slow solvent molecular motion enough to overcome obstruction by solute particles.

C. lower than the freezing point of the solvent alone because lower temperature is required to accelerate solvent molecular motion enough to overcome obstruction by solute particles.

D. higher than the freezing point of the solvent alone because higher temperature is required to accelerate solvent molecular motion enough to overcome obstruction by solute particles.

E. None of these are true.

I looked for a good web site and couldn't find one. I think the answer you want is B.