Which of these belongs in the empty box?
Electing a president
National power versus states' rights
Slaves used to determine representation
Taxation of exports
![Which of these belongs in the empty box Electing a president National power versus states rights Slaves used to determine representation Taxation of exports class=](https://us-static.z-dn.net/files/de9/84dedab4bc7a796cf1e5f30ce0c73d6c.png)