Respuesta :
Seeing how the Great Depression was long gone since 1939, A would be incorrect, and World War Two started in 1939(US entered the war in 1941) so B would make no sense either. The integration problem happened in the 60's so that would be incorrect as well, using the process of elimination the correct answer would be D) The United States and the Soviet Union had been involved in the Cold War for about four decades.