What important role do third parties often play in us national elections?
a) causing major parties to fight one another
b) breaking up major parties' dominance
c) challenging people with more choices
d) generating malice for larger parties

The third parties in the United States national elections play the vital role of B. breaking up major parties' dominance. The electoral system in the US has two main parties; however, third parties are present in order to ensure that the people voting have other options. Moreover, they also raise awareness for different problems and provide different perspectives, which the major parties then must tackle.