In the 1920s, employers embraced the american plan, which: advocated the "open shop." advocated government regulation of business. was applauded by the american federation of labor. was another term for americanization

The correct answer is that employers "advocated the open shop" concept.

This open shop concept essentially states that an individual does not have to join a union when working for a company or institution. This would help employers, as those who did not unionize had less power to negotiate their working conditions and pay rates. During this time, employers tried to portray unions as un-American in order to convince citizens that these unions were not a necessary part of the workforce.