Radio is responsible for which of the following changes during the 1920s? A. It heightened ethnic boundaries because broadcasters offered a variety of foreign-language programming. B. It furthered public education because broadcasters offered educational content. C. It enabled American homogenization by creating and publicizing national trends. D. It enabled special-interest groups to organize more effectively by broadcasting their messages to a wider audience.

Radio is responsible for which of the following changes during the 1920s? A. It heightened ethnic boundaries because broadcasters offered a variety of foreign-language programming. B. It furthered public education because broadcasters offered educational content. C. It enabled American homogenization by creating and publicizing national trends. D. It enabled special-interest groups to organize more effectively by broadcasting their messages to a wider audience.