Which of these amendments addresses the right to vote regardless of sex?

The 19th Amendment to the United States Constitution is significant because it specifically grants women the right to vote, thus addressing the issue of voting rights in relation to gender. Ratified in 1920, this amendment states that the right to vote cannot be denied or abridged on the basis of sex. This was a crucial milestone in the women's suffrage movement, which fought for equal voting rights for women, and marks a major step toward gender equality in the electoral process.

In terms of context, the 15th Amendment pertains to the right to vote being granted regardless of race, color, or previous condition of servitude, but it does not address gender. The 21st Amendment repeals the prohibition of alcohol but is unrelated to voting rights. The 24th Amendment eliminates poll taxes in federal elections, thus removing financial barriers to voting, but it does not specifically address voting rights in relation to sex. Therefore, the 19th Amendment is the clear answer regarding the right to vote regardless of sex.