How did the union break its treaty with the five tribes when the civil war started?

a.
to create a peace treaty and resettle plains tribes on reservations
b.
to pacify plains tribes and give them land
c.
to acquire more land for white settlers
d.
to punish plains tribes that raided white settlements

to create a peace treaty and resettle (A)

Explanation:

they broke off their first treaty to create the peace treaty to have land to resettle on.

i don't see how you want other people to do your work for you and it is like you are just handing your assignment to anybody else and having them deal with it instead of your self i thought this site was for asking questions and somebody could you on it not just handing your work to somebody else to deal with it just saying don't mean to be mean just proving a fact.

explanation: