Why Did New Products Like Ivory Soap and Quaker Oats

Why did new products like Ivory Soap and Quaker Oats symbolize the continuing integration of the economy in America's Gilded Age?

A) They were consumer products manufactured with new technologies.
B) These products catered particularly to the appetites and desires of new immigrants.
C) These products were exemplary for the way in which mass consumption raised everyone's living standards.
D) These products were national brands, sold everywhere across the United States thanks to the expanding railroad network.
E) These products were examples of how Gilded Age technologies helped develop the sustainable use of materials.