Amongst the “accomplishments” of the progressive movement of the 1890s–1920s, there were at least 4 amendments to the Constitution signed in this period. These included which of the following? A. Federal income tax, Direct election of Senators, and Women’s right to vote B. End of Slavery, Voting Rights, and Citizenship C. Limits on Corporations to give Campaign Donations, Equal Rights for Women, and Civil Rights. D. Freedom of Speech, Religion, and the Right to Arm Bears.

"A" would be the correct answer. The 16th amendment, allowing a federal income tax, went into effect in 1913. The 17th amendment also went into effect in 1913, allowing the direct election of U.S. senators. Finally, the 18th amendment, extending women the right to vote, became effective in 1920.
While the importance of the 16th and the 18th amendments are obvious, the 17th amendment corrected a situation which people felt caused corruption, which was the right of state legislatures to appoint senators. Putting this choice into the hands of the people was believed to increase the average person's power and voice in a democracy. The 18th amendment, giving women the vote, also made the government more democratic by broadening the franchise.
The 16th amendment, increasing the power of the federal government to impose taxes, increased the power of the central government and laid the groundwork for a cohesive national social welfare state, which came into effect during the 1930s.