The correct answer is A) women formed suffrage groups.
The option that describes a significant social change during the Gilded Age is "women formed suffrage groups."
The Gilded Age was a term coined by American writer Mark Twain in his book "The Gilded Age: A Tale Today." This term refers to the time in the US from 1870 to the beginning of the 1900s. It was a time of economic expansion in the country, but it carried some corruption practices in the government and companies. During this period, the women formed suffrage groups started to form, such as the International Council of Women and the International Women Suffrage Alliance.