In 1854, the controversial Kansas-Nebraska Act, split two
existing political parties the Whig party and Jacksonian Democrats and led to
the creation of the Republican party. Kansas-Nebraska act overturned the Missouri
compromise and allowed settlers to decide whether slavery would be allowed in
their state. This led to the creation of the Republican party founded by anti-slavers
whose primary objective was fighting slavery.
The Zollverein was an economic union of 30 states. The correct option among all the options given in the question is option "b". Zollverein is actually a coalition of German states whose main agenda was to manage the tariffs and all the economic policies within the German territories. Later on it expanded to other European countries as well.