Question

Following WWI, the President of the United States, Woodrow Wilson, pushed for the formation of the Legue of Nations. It was a prequel to the United Nations.

Although the United States was the "creator" of this organization, we did not join because the legislature did not ratify the treaty. Which house of the legislature is
responsible for ratifying treaties?
a. house of representatives
b. the senate
c. the supreme court

Answer 1

The Senate

it is given power by the constitution to do this with a two thirds vote

Answer 2

the Senate maintains several powers to itself: it ratifies treaties by a two-thirds supermajority vote and confirms the appointments of the President by a majority vote. the consent of the House of Representatives is also necessary for the ratification of trade agreements and the confirmation of the Vice President.

so, b would be your answer :)