Which is most responsible for the rapid settlement of the great plains?

ba geologist finds four sedimentary rock she determines that no geologic events have shifted the layers she labeles them a,b,c,dbfrom top to bottom

"globalization has greatly impacted the united states and american citizens. first and foremost, globalization has spread american influence throughout the world. globalization has opened up more markets for the united states, which in effect american companies sell their products worldwide. there has been a rise of multinational corporations and their influence has greatly increased."