The key difference between the views of the Whigs and Democrats and those in the Free-Soil Party is that the Whigs and Democrats embraced the idea of popular sovereignty. The Free-Soil Party, on the other hand, was firmly opposed to the expansion of slavery into the territories and advocated for free soil for free men, emphasizing the rights of free labor over slave labor.
So, the correct response is: The Whigs and Democrats embraced the idea of popular sovereignty.