The main reason why a freedman would agree to become a sharecropper is because he had practically no money--having just been freed from slavery. Working for someone else on poor terms was one of the only ways to survive.
Critics of the Articles of Confederation argued that it was far too "weak" in the sense that it didn't give the federal government enough power over the states. This became especially evident after Shays' Rebellion, which proved very difficult to put down.
I believe the answer is A. Spain