I need help plz. How did conflicts in Europe and Asia in the first half of the 20th century lead to an expansion of America’s role in the world?

The major impact third parties have on presidential elections has been to.. a. encourage larger vote turnout b. recruiter leader from the democratic and republican party to run for president c. generate increased party identification among the electorate d. developing issues that are later adopted by the major political parties e. drawn off of votes from the major parties to throw election into the house representatives