Atheory that assumes that conflict between different parts of society leads to changes in the way society works is called
a. change theory.
b. conflict theory.
c. group theory.
d. latent theory.

The theory that assumes that conflict between different parts of society leads to changes in the way society works is called conflict theory. Conflict theorists believe that social change is the result of the struggle between the various social groups, It has led to the development of new political ideas and politics changes the way a society works.

Theories where the main aspect is in conflict; in this case a theory which assumes conflict between different parts of society will lead to changes in the way how society works, are called conflict theories. 

The correct answer is for that reason B - conflict theory. 

The northern states wanted to get rid of slavery

could be wrong but I think they seperated because they where afriad of taxes too