Difference between trade barriers and migration barriers

Plz 50 points answer only if you know and don't copy answer describe how the geography of the korean peninsula affected where people settled and how they lived.

Which of the following encouraged westward expansion? a.the government decreased the price of federal land. b.each of these represents actions taken to encourage westward expansion. c.the government decreased the price of federal land d.the second national bank lowered the cost of borrowing money (reduced interest rates)

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