Final answer:
Congress strengthened voting rights in 1970 by the enforcement of the Voting Rights Act of 1965, which helped eliminate racially discriminatory voting practices including literacy tests, and by overseeing elections to protect the rights of voters.
Step-by-step explanation:
In 1970, Congress strengthened voting rights by the extension and enforcement of the Voting Rights Act of 1965. This act was monumental in securing the right to vote for racial minorities, especially in the South, by prohibiting state laws that denied voting rights based on race. It included measures such as the banning of literacy tests, and it authorized the federal government to oversee elections and intervene whenever discriminatory practices were suspected. The Voting Rights Act is regarded as the most effective piece of civil rights legislation ever enacted in the country.
Also of significance was the ratification of the Twenty-Fourth Amendment in 1964, which ended poll taxes, further contributing to the support and protection of voting rights for all citizens. These efforts were a direct response to recognize and rectify the years of discrimination that had kept, predominantly African Americans, from exercising their right to vote. The correct answer to the student's question is A) Voting Rights Act.