Which of the Following Trends Occurred Over the Course of the Twentieth

Which of the following trends occurred over the course of the twentieth century and helped transform the political map of the world and the relationships between the countries that appear on it?

A) Many former colonies gained independence.
B) Regional political and economic associations emerged.
C) China arose as a challenger to the century-long economic and political dominance of the United States.
D) Both A and B
E) All of the above