How did the Union break its treaty with the Five Tribes when the Civil War started?
A.
They refused to pay the Five Tribes annuities required by treaties.
B.
They left the region and could no longer protect the tribes from attack.
C.
They attacked forts controlled by the Five Tribes.
D.
They drafted tribe members into Union regiments, sending them to fight against the Confederacy.

The correct answer is option A.  They refused to pay the Five Tribes annuities required by treaties.

Explanation:

The civil war affected the tribes in a negative way. The union broke the treaties that they had made with the tribes while settling in. In order to do so, they refused to pay for the annuities that were decided as per the treaties. This obviously led to a harsher relationship between the union and the tribes which resulted in diffusion of treaties.

the correct answer is:

b) a rich merchant.