What organization did Susan B. Anthony notably advocate for?

Susan B. Anthony is renowned for her tireless advocacy for women's rights, particularly focusing on women's suffrage—the right for women to vote. Throughout her life, she worked to challenge the societal norms that restricted women’s roles and denied them equal legal rights. She co-founded the National Woman Suffrage Association and held rallies, delivered speeches, and organized campaigns to raise awareness about the importance of women's voting rights. Her pivotal contributions helped shape the women's rights movement in the United States and directly influenced the eventual passage of the 19th Amendment, which granted women the right to vote. This significant legacy is why advocating for women's rights is the correct answer.