What Was the Relationship Between the Great War and the Great

What was the relationship between the Great War and the Great Migration?

A) Due to the increased opportunities for African Americans during wartime, race riots and other violent altercations ceased as civilians focused on the war effort.
B) Because a large number of immigrants were entering the United States, many as refugees, the war effort tripled in size and American industry was forever transformed.
C) Due to mobilization for the war, employment efforts led by northern businesses were directed at African Americans as well as whites for the first time, causing many to move north.
D) Because Mexican Americans were forbidden from enlisting in the military, many of them pursued jobs in urban areas
E) Because many American soldiers continued to find excitement and have positive experiences fighting in Europe, a large number decided to remain there after the war ended.