Question

Third party systems play a highly important role in the

Answer 1

I agree with the person above - third party systems play a highly important role in the A. strengthening of the two major parties.
A third party is a party that didn't have enough votes to compete with the dominant two parties. In a two-party system, such as America, the third party is only there to reinforce the dominant two parties, by strengthening their influence.

Answer 2

The answer would be A) strengthening of the two major parties