The correct answer is: "the voting age was lowered to the age of eighteen."
The Twenty-sixth Amendment to the US Constitution was ratified in 1971 and banned both the federal and state goverments from preventing any US citizen from the right to vote, as long as he/she had already turned 18 yearls old. Throught the enactment of this amendment, the voting age was lowered from 21 to 18.
