We see one of the major effect of The Great Depression was widespread unemployment. There were more than 10 million people unemployed in the US. So resolving unemployment was main issue of New Deal. Under New Deal we see The Civilian Conservative Corps ( CCC ) was created which employed 2.5 million young men on conservation and reforestation projects.
So in between The Great Depression and The New Deal, widespread unemployment suits the most. The Unemployment was an effect of The Great Depression and a cause of establishment of New Deal as well.
I think it’s B. Because all the others don’t really make any sense the war lasted 4 years and was the turning point in technological advances like tanks gas etc. and it came from both sides which lead to a stalemate aka trench warfare. Hope this helps!
