Which of the Following Is One of the Arguments of the "Glut

Which of the following is one of the arguments of the "glut thesis"?

A) The financial panics of the 1870s and the 1890s were the result of the overproduction of goods.
B) Americans might require a new frontier in order to ensure the survival of the nation's democracy.
C) Blacks are to be separated from whites in public transport.
D) The presence of the western frontier had impeded the development of democracy and capitalism.
E) White Christian Americans stood at the top of civilization.