What are two reasons the us has become one of the most powerful countries in the world

Yes. Look.  It's not a popular answer these days to say, "The US is the most powerful nation!"  There are a LOT of people who (for varying reasons, many of which are respectable) want this to not be true.  But wanting a thing doesn't mean that it's true.  Ideology may blind us.  And whether you like the US or not, it is the most powerful nation and will be the most powerful nation for a while to come, most of us will be dead when the time comes that it isn't (if ever) and even then —if that happens— it will only be missing that spot by a small margin.This is because the US isn't just the US.  Again, I know it's fun to talk about how dumb the US is.  It almost falls into that George W. Bush category of disliking a thing so much, that it allows us to say whatever pejorative we want, without regard for intellectual honesty on the matter.  But the US ain't dumb.  It inherited hegemony from the British Empire and continued that legacy and built a network of incredibly powerful alliances that will not suddenly go away the moment China surpasses the US in general potential.And that's the really important thing to remember, is in understanding what "power" means. I don't deal in predicting the future, but it's pretty obvious that China will continue to grow economically for a generation.  It isn't just economic size (the US is losing that status in a few years).  China's economy will be bigger NOT because of some magic number, but because of 1.3 billion people multiplied by a really, REALLY low GDP per capita.  And that's the thing, how wealthy will the Chinese people get?But most reasonable estimates point out that there is a dangerous point in economies that are really, REALLY tricky to navigate.  There's a "glass ceiling" that many countries discover where the high expectations of earnings prevent businesses from investing a lot in their country because it was precisely the low wages those companies were after.  This doesn't mean nations can't get there.  Spain, Italy, Singapore, Taiwan, South Korea and others have crossed that "glass ceiling" where they moved into fully industrialized economies with nice high per capita incomes. 

The answer is option c.