Many states had rivers as borders, but Congress could not regulate how states should share the rivers for trade. What kind of problems might come up as neighboring states used the
river between them to transport goods?

idk

explanation:

the most famous of all the units fighting in cuba, the "rough riders" was the name given to the first u.s. volunteer cavalry under the leadership of theodore roosevelt. roosevelt resigned his position as assistant secretary of the navy in may 1898 to join the volunteer cavalry. the original plan for this unit called for filling it with men from the indian territory, new mexico, arizona, and oklahoma. however, once roosevelt joined the group, it quickly became the place for a mix of troops ranging from ivy league athletes to glee-club singers to texas rangers and indians.

hello, your actual correct answer is c. taxes.

factories are actually the second biggest but on your optian list its taxes.