How did the presence of the border states illustrate a difference between the union and confederacy?

a. the confederacy had more internal political disagreements than the union.

b. the confederacy had more states on its side than the union.

c. the union's population was divided on the issue of slavery.

d. the union's population was united in believing slavery was wrong.

The rise of advertising in the 1920s. i am good with seeing how advertisements shape the roaring twenties and how it developed a new way of life through modern days. but i am not sure what the details of advertising in the 1920s were. if possible can you send me links (preferrably credential links) to sources that maybe show like the first company to start advertising through the radio, how advertising benefits (statistics graphs), etc.