Question

What factors helped to create a national culture (one that all regions of America share)?

Answer 1

Assuming that this is referring to the same list of options that was posted before with this question, the best options would be the expansion of the media and more immigration, since both of these things lead to a "diffusion" of cultures. 

Answer 2

Answer:

Assuming that this is referring to the same list of options that was posted before with this question, the best options would be the expansion of the media and more immigration, since both of these things lead to a "diffusion" of cultures.

Explanation: