Why Did Bourne Speak of a New "Trans-National" Culture in America

Why did Bourne speak of a new "trans-national" culture in America?

A) because when immigrants returned to their home countries, they always took portions of American culture with them
B) because U.S. foreign policy was based on invading other countries
C) because immigration was ruining America's national character
D) because America was formed by different peoples and not a single nationality
E) because the only way for the United States to become a world leader was by copying the best features and programs of other nations