The answer is going to be the Gentleman's Agreement. This agreement was between United States and the Empire of Japan, not Mexico.
Du Bois, he was the first doctoral African American to revive a Ph.D from Harvard UN. in 1895
A and B is out because these undoubtedly are unique Chinese achievements. So is D. The Chinese are infamous for these things. Other achievements include gunpowder, fireworks, ect.
C is basically the answer because the chinese aren't the only race or country to do so. Many people have done it in the past before them and present in the terms of civilization. It isn't simply uniquely or originally from them.
The launching of the Russian satellite "Sputkik" was a major even in the Cold War and sparked the "space race". "<span>It raised fears that the Soviet Union could drop a nuclear bomb directly on the United States"</span> would be the best answer.
It's either B or D because they weren't allowed to own property and could not vote
