A federal republic<span> is a federation of states with a republican form of government.</span>
I think the answer is D:all of the above.
Explanation:
Using a maps scale most of the time involves some math. Usually you'd take a distance on the map (in inches) and multiply it to whatever that maps scale is, for example 1:500. A maps scale is used to show larger distances on a map in a ratio form to show the real ground distance. Showing 10 miles on a single piece of paper would be rather difficult if there weren't a scale
This paragraph should help you out :)