It would be the conclusion.
In essence, the author is stating that the degree of diversity that exists in the United States is much greater than any other country in the world. Any time there is a lot of diversity, there is the potential for problems.
The answer is D
Corrupted has a negative connotation, like distracted. “The present”=latest new. You is figurative; the author does not literally mean a toy, but a new thing.
