Answer:
C: If the country is big enough, one part of it might be closer to a lucrative trade area, such a useful water system for trade or a hotspot for a highly desired resource. An example of this is how New York was good for trade because of how it could have ports, which helped it gain money and then generally modernize/advance. Compare this to Wyoming, however, which isn't as close to a lucrative water system (or I don't think it is, I guess) as New York is. This leads to New York and its city being quite wealthy and advanced on account of how lucrative it was, but other areas, like Wyoming, weren't as close to ones like it. So in states, if one is closer to a lucrative spot, be it a water system, a mineral deposit, or something else, it may become significantly wealthier than areas that aren't as close to it.
Explanation:
I don't think I could put that in the comments as it didn't let me send it, I think, but this is the last part of it, C, I guess.
