The correct answer is C) it declined because it had achieved its main goal.
What happened to the women's rights movement of the 1920s after it earned the right to vote was that it declined because it had achieved its main goal.
Women have always played a major role in American society, but their rights were limited. That is why in 1848, tho brave women organized the Seneca Falls Convention in the city of Seneca Falls, New York. They were Elizabeth Cady Stanton and Susan B. Anthony, that lobbied Congressmen to pass legislation to allow women the right to vote. After the movement earned the right to vote it declined because it had achieved its main goal.