What is the senate’s only defense to a filibuster?

To invoke cloture.

Explanation:

The filibuster is a political tactic or procedure employed by members of the Senate, wherein one or more members intentionally give long and often irrelevant speeches to debate a proposed piece of legislation, in order to delay or prevent the chamber from voting on a bill, an amendment, or motion,

When this happens, the Senate’s only defense to a filibuster is to invoke cloture, which is the only formal procedure to end a filibuster. However, only if three-fifths of the Senators vote in the affirmative, cloture is invoked.

Afterward, the Senate sets a series of conditions and constraints to end the debate such as only 30-Hour Time Cap to consider the bill, amendment or motion in question, and 1-hour time cap of debate per senator.

regarding the law, the 15th amendment was specifically designed thinking in the rights of black free men.

even though ratified on february 3, 1870, the promise of the 15th amendment would not be fully applied for a long time.poll taxes and literacy tests would allow southern states disenfranchise african americans. only in 1965 the voting rights for african americans would be actually able to vote in the south.

in 1965, president johnson signed the voting rights act, which aimed to overcome legal barriers that prevented african americans from voting as it was guaranteed by the 15th amendment to the u.s. constitution.

formulating the initial idea for the policy

answer is c.