How would migration from the rust belt to the sun belt change demographics in the rust belt?

a.there would be fewer contributing citizens to the growth of the area.

b.there would be more sun belt citizens moving north.

c.there would be more canadian migration into the rust belt.

d.there would be more west coast workers moving into the rust belt.

the American people tame  their country's frontiers in order to make safe and expand the boundaries of their country.

Explanation:

The people of American tame  their country's frontiers for making the in order to make safe and expand the boundaries of their country on the barren vast land that were present beyond the frontier line. According to Frederick Jackson Turner, the environment on the frontier is hard and the advancement of the frontier occurs in order to include the frontier areas in the country and proper government should be made in these areas. These areas were also captured due to increase in population.