Final answer:
Elizabeth Cady Stanton was the leading proponent of women's suffrage who did not support the passage of the Fourteenth and Fifteenth Amendments until women were included in the right to vote, representing a divisive moment in the movement for equality. Option B is the correct answer.
Step-by-step explanation:
The leading proponent of women's suffrage who did not support the passage of the Fourteenth and Fifteenth Amendments as long as women were still denied the right to vote was Elizabeth Cady Stanton. She, alongside Susan B. Anthony, were prominent and ardent abolitionists who after the Civil War felt betrayed by the exclusion of women from the Fifteenth Amendment. They launched an independent women's movement, and Anthony drafted an amendment similar to the 15th, known as the Anthony Amendment, which was introduced in the Senate in 1878, aiming to guarantee women's right to vote.
Stanton and Anthony sought to achieve universal suffrage, yet they were willing to partner with white supremacists to forward their cause, showing their prioritization of women's suffrage over the broader equality movement. Despite their significant contributions to abolitionism and their struggle for women's rights, the exclusion of women from the Fourteenth and Fifteenth Amendments led to a divisive moment in the movement for equality.