Private. The answer is private
The quote from the Constitution that describes the Senate is the first one - a. No person who shall not have attained to the Age of thirty Years, and beennine Years a Citizen of the United States, and who shall not, when elected, be an Inhabitant of that State for which he shall be chosen.
I believe the answer is: Primary
For example, let's say take a look at normal employees at a company.
For most of them, the main reason they spend their time to do the job correctly is to obtain money/salary even though they have to spend their time being scolded by unlikable boss.
In the scenario above, we can say that money is the primary reinforcer for the target behavior
If i'm not mistaken, the European Union practices a Federal government structure :)
